Python join array to string

Question

The string join() method returns a string by joining all the elements of an iterable (list, string, tuple), separated by the given separator.

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Syntax of String join()
join() Parameters
Return Value from join()
Example 1: Working of the join() method
Example 2: The join() method with sets
Example 3: The join() method with dictionaries
Example 1: Joining with an empty string
Example 2: Joining String with lists using join()
Example 3: Joining String with sets using join()
Example 4: Joining String with a dictionary using join()
How do you join an array of strings in Python?
What is join () in Python?
How do you join a list element into a string?
How do you join a list of objects in Python?

Example

text = ['Python', 'is', 'a', 'fun', 'programming', 'language']

# join elements of text with space
print(' '.join(text))

# Output: Python is a fun programming language

Syntax of String join()

The syntax of the join() method is:

string.join(iterable)

join() Parameters

The join() method takes an iterable (objects capable of returning its members one at a time) as its parameter.

Some of the example of iterables are:

Native data types - List, Tuple, String, Dictionary and Set.
File objects and objects you define with an __iter__() or __getitem()__ method.

Note: The join() method provides a flexible way to create strings from iterable objects. It joins each element of an iterable (such as list, string, and tuple) by a string separator (the string on which the join() method is called) and returns the concatenated string.

Return Value from join()

The join() method returns a string created by joining the elements of an iterable by the given string separator.

If the iterable contains any non-string values, it raises the TypeError exception.

Example 1: Working of the join() method

# .join() with lists
numList = ['1', '2', '3', '4']
separator = ', '
print(separator.join(numList))

# .join() with tuples
numTuple = ('1', '2', '3', '4')
print(separator.join(numTuple))

s1 = 'abc'
s2 = '123'

# each element of s2 is separated by s1
# '1'+ 'abc'+ '2'+ 'abc'+ '3'
print('s1.join(s2):', s1.join(s2))

# each element of s1 is separated by s2
# 'a'+ '123'+ 'b'+ '123'+ 'b'
print('s2.join(s1):', s2.join(s1))

Output

1, 2, 3, 4
1, 2, 3, 4
s1.join(s2): 1abc2abc3
s2.join(s1): a123b123c

Example 2: The join() method with sets

# .join() with sets
test = {'2', '1', '3'}
s = ', '
print(s.join(test))

test = {'Python', 'Java', 'Ruby'}
s = '->->'
print(s.join(test))

Output

2, 3, 1
Python->->Ruby->->Java

Note: A set is an unordered collection of items, so you may get different output (order is random).

Example 3: The join() method with dictionaries

# .join() with dictionaries
test = {'mat': 1, 'that': 2}
s = '->'

# joins the keys only
print(s.join(test))




test = {1: 'mat', 2: 'that'}
s = ', '
# this gives error since key isn't string
print(s.join(test))

Output

mat->that
Traceback (most recent call last):
  File "...", line 12, in 
TypeError: sequence item 0: expected str instance, int found

The join() method tries to join the keys (not values) of the dictionary with the string separator.

Note: If the key of the string is not a string, it raises the TypeError exception.

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join() is an inbuilt string function in Python used to join elements of the sequence separated by a string separator. This function joins elements of a sequence and makes it a string.

Syntax: string_name.join(iterable)

Parameters:
Iterable – objects capable of returning their members one at a time. Some examples are List, Tuple, String, Dictionary, and Set
Return Value: The join() method returns a string concatenated with the elements of iterable.
Type Error: If the iterable contains any non-string values, it raises a TypeError exception.

Example 1: Joining with an empty string

Here, we join the list of elements using the join method.

Python3

list1 = ['g', 'e', 'e', 'k', 's']

print("".join(list1))

list1 = " geeks "

print("$".join(list1))

Output:

geeks
$g$e$e$k$s$

Example 2: Joining String with lists using join()

Here, we join the tuples of elements using the join() method in which we can put any character to join with a string.

Python3

list1 = ('1', '2', '3', '4')

s = "-"

s = s.join(list1)

print(s)

Output:

1-2-3-4

Example 3: Joining String with sets using join()

In this example, we are using a Python set to join the string.

Note: Set contains only unique value therefore out of two 4 one 4 is printed.

Python3

list1 = {'1', '2', '3', '4', '4'}

s = "-#-"

s = s.join(list1)

print(s)

Output:

1-#-3-#-2-#-4

Example 4: Joining String with a dictionary using join()

When joining a string with a dictionary, it will join with the keys of a Python dictionary, not with values.

Python3

dic = {'Geek': 1, 'For': 2, 'Geeks': 3}

string = '_'.join(dic)

print(string)

Output:

'Geek_For_Geeks'

How do you join an array of strings in Python?

Note: The join() method provides a flexible way to create strings from iterable objects. It joins each element of an iterable (such as list, string, and tuple) by a string separator (the string on which the join() method is called) and returns the concatenated string.

What is join () in Python?

join() is an inbuilt string function in Python used to join elements of the sequence separated by a string separator. This function joins elements of a sequence and makes it a string. Syntax: string_name.join(iterable)

How do you join a list element into a string?

If you want to concatenate a list of numbers ( int or float ) into a single string, apply the str() function to each element in the list comprehension to convert numbers to strings, then concatenate them with join() .

How do you join a list of objects in Python?

Use list comprehension and str..

class Obj:.

def __str__(self):.

return 'I am an object! '.

object_list = [Obj(), Obj(), Obj()].

object_string = ', '. join([str(x) for x in object_list]).

print(object_string).

programming python Python string join Join array Python String join Join string JavaScript

Python join array to string

Example

Syntax of String join()

join() Parameters

Return Value from join()

Example 1: Working of the join() method

Example 2: The join() method with sets

Example 3: The join() method with dictionaries

Example 1: Joining with an empty string

Python3

Example 2: Joining String with lists using join()

Python3

Example 3: Joining String with sets using join()

Python3

Example 4: Joining String with a dictionary using join()

Python3

How do you join an array of strings in Python?

What is join () in Python?

How do you join a list element into a string?

How do you join a list of objects in Python?

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