Làm cách nào để bạn tạo và thêm dữ liệu vào tệp csv trong python?

Tệp CSV đến từ đâu?

Các tệp CSV thường được tạo bởi các chương trình xử lý lượng lớn dữ liệu. Chúng là một cách thuận tiện để xuất dữ liệu từ bảng tính và cơ sở dữ liệu cũng như nhập hoặc sử dụng dữ liệu đó trong các chương trình khác. Ví dụ: bạn có thể xuất kết quả của chương trình khai thác dữ liệu sang tệp CSV rồi nhập tệp đó vào bảng tính để phân tích dữ liệu, tạo biểu đồ cho bản trình bày hoặc chuẩn bị báo cáo để xuất bản

Các tệp CSV rất dễ làm việc theo chương trình. Bất kỳ ngôn ngữ nào hỗ trợ nhập tệp văn bản và thao tác chuỗi (như Python) đều có thể hoạt động trực tiếp với tệp CSV

Đọc tệp CSV với import csv with open('employee_birthday.txt') as csv_file: csv_reader = csv.reader(csv_file, delimiter=',') line_count = 0 for row in csv_reader: if line_count == 0: print(f'Column names are {", ".join(row)}') line_count += 1 else: print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.') line_count += 1 print(f'Processed {line_count} lines.') 7

Việc đọc từ tệp CSV được thực hiện bằng đối tượng

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

Đây là tệp

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Đây là mã để đọc nó

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Điều này dẫn đến đầu ra sau

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

Mỗi hàng được trả về bởi

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Đọc tệp CSV vào từ điển với import csv with open('employee_birthday.txt') as csv_file: csv_reader = csv.reader(csv_file, delimiter=',') line_count = 0 for row in csv_reader: if line_count == 0: print(f'Column names are {", ".join(row)}') line_count += 1 else: print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.') line_count += 1 print(f'Processed {line_count} lines.') 7

Thay vì xử lý danh sách các phần tử

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Một lần nữa, tệp đầu vào của chúng tôi,

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Đây là mã để đọc nó như một cuốn từ điển lần này

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Điều này dẫn đến đầu ra giống như trước đây

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

Các khóa từ điển đến từ đâu? . Nếu bạn không có những thứ này trong tệp CSV của mình, bạn nên chỉ định các khóa của riêng mình bằng cách đặt tham số tùy chọn

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Tham số Python CSV Column names are name, department, birthday month John Smith works in the Accounting department, and was born in November. Erica Meyers works in the IT department, and was born in March. Processed 3 lines. 7 tùy chọn

Đối tượng

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

• import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  49 chỉ định ký tự được sử dụng để phân tách từng trường. Mặc định là dấu phẩy (

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  40)

• import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  41 chỉ định ký tự được sử dụng để bao quanh các trường có chứa ký tự phân cách. Mặc định là trích dẫn kép (

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  42)

• import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  43 chỉ định ký tự được sử dụng để thoát khỏi ký tự phân cách, trong trường hợp dấu ngoặc kép không được sử dụng. Mặc định là không có ký tự thoát

Các thông số này xứng đáng được giải thích thêm. Giả sử bạn đang làm việc với tệp

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Tệp CSV này chứa ba trường.

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Có ba cách khác nhau để xử lý tình huống này

• Sử dụng dấu phân cách khác
  Bằng cách đó, dấu phẩy có thể được sử dụng một cách an toàn trong chính dữ liệu. Bạn sử dụng tham số tùy chọn

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  49 để chỉ định dấu phân cách mới.

• Gói dữ liệu trong dấu ngoặc kép
  Bản chất đặc biệt của dấu phân cách bạn chọn bị bỏ qua trong chuỗi được trích dẫn. Do đó, bạn có thể chỉ định ký tự được sử dụng để trích dẫn với tham số tùy chọn

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  41. Miễn là ký tự đó cũng không xuất hiện trong dữ liệu, bạn vẫn ổn.

• Thoát các ký tự phân cách trong dữ liệu
  Các ký tự thoát hoạt động giống như trong các chuỗi định dạng, vô hiệu hóa việc diễn giải ký tự được thoát (trong trường hợp này là dấu phân cách). Nếu một ký tự thoát được sử dụng, nó phải được chỉ định bằng tham số tùy chọn

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  43.

Viết tệp CSV bằng import csv with open('employee_birthday.txt') as csv_file: csv_reader = csv.reader(csv_file, delimiter=',') line_count = 0 for row in csv_reader: if line_count == 0: print(f'Column names are {", ".join(row)}') line_count += 1 else: print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.') line_count += 1 print(f'Processed {line_count} lines.') 7

Bạn cũng có thể ghi vào tệp CSV bằng đối tượng

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

column 1 name,column 2 name, column 3 name
first row data 1,first row data 2,first row data 3
second row data 1,second row data 2,second row data 3
...

Tham số tùy chọn

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

• Nếu

  Column names are name, department, birthday month
      John Smith works in the Accounting department, and was born in November.
      Erica Meyers works in the IT department, and was born in March.
  Processed 3 lines.
  

  7 được đặt thành

  Column names are name, department, birthday month
      John Smith works in the Accounting department, and was born in November.
      Erica Meyers works in the IT department, and was born in March.
  Processed 3 lines.
  

  9, thì

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  50 sẽ chỉ trích dẫn các trường nếu chúng chứa

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  49 hoặc

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  41. Đây là trường hợp mặc định
• Nếu

  Column names are name, department, birthday month
      John Smith works in the Accounting department, and was born in November.
      Erica Meyers works in the IT department, and was born in March.
  Processed 3 lines.
  

  7 được đặt thành

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  54, thì

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  50 sẽ trích dẫn tất cả các trường
• Nếu

  Column names are name, department, birthday month
      John Smith works in the Accounting department, and was born in November.
      Erica Meyers works in the IT department, and was born in March.
  Processed 3 lines.
  

  7 được đặt thành

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  57, thì

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  50 sẽ trích dẫn tất cả các trường chứa dữ liệu văn bản và chuyển đổi tất cả các trường số thành kiểu dữ liệu

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  59
• Nếu

  Column names are name, department, birthday month
      John Smith works in the Accounting department, and was born in November.
      Erica Meyers works in the IT department, and was born in March.
  Processed 3 lines.
  

  7 được đặt thành

  column 1 name,column 2 name, column 3 name
  first row data 1,first row data 2,first row data 3
  second row data 1,second row data 2,second row data 3
  ...
  

  61, thì

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  50 sẽ thoát khỏi dấu phân cách thay vì trích dẫn chúng. Trong trường hợp này, bạn cũng phải cung cấp giá trị cho tham số tùy chọn

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  43

Đọc lại tệp ở dạng văn bản thuần túy cho thấy tệp được tạo như sau

Column names are name, department, birthday month
    John Smith works in the Accounting department, and was born in November.
    Erica Meyers works in the IT department, and was born in March.
Processed 3 lines.

Viết tệp CSV từ một từ điển với import csv with open('employee_birthday.txt') as csv_file: csv_reader = csv.reader(csv_file, delimiter=',') line_count = 0 for row in csv_reader: if line_count == 0: print(f'Column names are {", ".join(row)}') line_count += 1 else: print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.') line_count += 1 print(f'Processed {line_count} lines.') 7

Vì bạn có thể đọc dữ liệu của chúng tôi trong từ điển, nên thật công bằng khi bạn cũng có thể viết nó ra từ từ điển

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Khác với

column 1 name,column 2 name, column 3 name
first row data 1,first row data 2,first row data 3
second row data 1,second row data 2,second row data 3
...

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

column 1 name,column 2 name, column 3 name
first row data 1,first row data 2,first row data 3
second row data 1,second row data 2,second row data 3
...

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Đoạn mã trên tạo ra tệp đầu ra sau

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Đọc tệp CSV với import csv with open('employee_birthday.txt') as csv_file: csv_reader = csv.reader(csv_file, delimiter=',') line_count = 0 for row in csv_reader: if line_count == 0: print(f'Column names are {", ".join(row)}') line_count += 1 else: print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.') line_count += 1 print(f'Processed {line_count} lines.') 8

Để thể hiện một số sức mạnh của khả năng CSV của

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Đọc CSV thành

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Đó là nó. ba dòng mã và chỉ một trong số chúng đang thực hiện công việc thực tế.

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Sau đây là một số điểm đáng lưu ý

• Đầu tiên,

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  8 nhận ra rằng dòng đầu tiên của CSV chứa tên cột và tự động sử dụng chúng. Tôi gọi đây là Thiện
• Tuy nhiên,

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  8 cũng đang sử dụng các chỉ số số nguyên dựa trên số không trong

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  404. Đó là bởi vì chúng tôi đã không nói cho nó biết chỉ mục của chúng tôi nên là gì

• Hơn nữa, nếu bạn xem các loại dữ liệu của các cột của chúng tôi, bạn sẽ thấy

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  8 đã chuyển đổi chính xác các cột

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  411 và

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  412 thành số, nhưng cột

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  413 vẫn là một

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  42. Điều này dễ dàng được xác nhận trong chế độ tương tác

  >>>

  import csv
  
  with open('employee_birthday.txt') as csv_file:
      csv_reader = csv.reader(csv_file, delimiter=',')
      line_count = 0
      for row in csv_reader:
          if line_count == 0:
              print(f'Column names are {", ".join(row)}')
              line_count += 1
          else:
              print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
              line_count += 1
      print(f'Processed {line_count} lines.')
  

  47

Hãy giải quyết từng vấn đề một. Để sử dụng một cột khác làm chỉ mục

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Bây giờ trường

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

Tiếp theo, hãy sửa kiểu dữ liệu của trường

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')

import csv

with open('employee_birthday.txt') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print(f'Column names are {", ".join(row)}')
            line_count += 1
        else:
            print(f'\t{row[0]} works in the {row[1]} department, and was born in {row[2]}.')
            line_count += 1
    print(f'Processed {line_count} lines.')