Hướng dẫn duplicate strings in python

I'm just starting some string manipulations and found this question. I was probably trying to do something like the OP, "usual me". The previous answers did not clear up my confusion, but after thinking a little about it I finally "got it".

Nội dung chính

• Copying the string
• Use an Empty String to Get a Copy String in Python
• Use Slicing to Copy a String in Python
• Use the str() Function to Copy a String in Python
• Use String Formatting to Copy a String in Python
• Related Article - Python String
• How do I repeat a string in Python?
• How do you make a copy of a string?
• How do you make duplicates in Python?
• What does Copy () do in Python?

Nội dung chính

• Copying the string
• Use an Empty String to Get a Copy String in Python
• Use Slicing to Copy a String in Python
• Use the str() Function to Copy a String in Python
• Use String Formatting to Copy a String in Python
• Related Article - Python String
• How do I repeat a string in Python?
• How do you make a copy of a string?
• How do you make duplicates in Python?
• What does Copy () do in Python?

As long as a, b, c, d, and e have the same value, they reference to the same place. Memory is saved. As soon as the variable start to have different values, they get start to have different references. My learning experience came from this code:

import copy
a = 'hello'
b = str(a)
c = a[:]
d = a + ''
e = copy.copy(a)

print map( id, [ a,b,c,d,e ] )

print a, b, c, d, e

e = a + 'something'
a = 'goodbye'
print map( id, [ a,b,c,d,e ] )
print a, b, c, d, e

The printed output is:

[4538504992, 4538504992, 4538504992, 4538504992, 4538504992]

hello hello hello hello hello

[6113502048, 4538504992, 4538504992, 4538504992, 5570935808]

goodbye hello hello hello hello something

In this tutorial, we are going to learn about multiple ways to copy a string in Python.

Copying the string

Consider, we have the following string:

To make a copy of a string, we can use the built-in slice syntax [:] in Python.

Example:

name = 'kelly'

copy = name[:]

print(copy) # 'kelly'

Similarly, we can also do it by assigning a string to the new variable.

name = 'kelly'

copy = name

print(copy) # 'kelly'

or we can use the str() function to create a string copy.

name = 'kelly'

copy = str(name)

print(copy) # 'kelly'

ostr = 'Web'
nstr = '' + ostr
print(nstr)

Web

ostr = 'Web'
nstr = ostr[:]
print(nstr)

Web

ostr = 'Web'
nstr = str(ostr)
print(nstr)

Web

ostr = 'Web'  
nstr = '%s' % ostr
print(nstr)

Web

How do I repeat a string in Python?

Use the syntax a_string * n with n as an integer to repeat a_string n number of times.

How do you make a copy of a string?

Copying one string to another - strcpy strcpy can be used to copy one string to another. Remember that C strings are character arrays. You must pass character array, or pointer to character array to this function where string will be copied. The destination character array is the first parameter to strcpy .

How do you make duplicates in Python?

In Python, we use = operator to create a copy of an object. You may think that this creates a new object; it doesn't. It only creates a new variable that shares the reference of the original object. Let's take an example where we create a list named old_list and pass an object reference to new_list using = operator.

What does Copy () do in Python?

The Python copy() method creates a copy of an existing list. The copy() method is added to the end of a list object and so it does not accept any parameters. copy() returns a new list.