Python integer list join

How to join a list of integers into a string in Python

How to join a list of integers into a string in Python. That’s the topic I want to introduce to you today. If you’re curious about this topic, read it all.

Join a list of integers into a string in Python

Use list comprehension.

List comprehension is a simple, easy-to-understand way to join a list of integers into a string.

• List comprehension will iterate through the elements of an integer list along with the str() function, which will convert the iterated elements into strings.

intList = [1, 2, 3, 4, 5] # Use list comprehension to convert a list of integers to a string intStr = ', '.join([str(i) for i in intList]) print(intStr) print(type(intStr))

• Create an empty string that stores the substrings.
• Use for loop iterate over the elements and convert the elements in the list to a string.
• Add substrings to the original empty string.
• Finally, remove the extra spaces at the end of the string.

intList = [1, 2, 3, 4, 5] # Create an empty string that stores the substrings. emptyStr = '' # Use for loop iterate over the elements and convert the elements in the list to a string. # Add substrings to the original empty string. for i in intList: emptyStr += str(i) + ', ' # Remove the excess element at the end of the string. newStr = emptyStr.rstrip(', ') print(newStr) print(type(newStr))

Use the join() function in conjunction with the map() function.

• str: Delimiter for string concatenation.
• object: List or tuple containing elements that are strings to be concatenated.

The join() function returns an object that is a character string of the elements of the specified list or tuple joined together by a delimiter.

• function: The function to execute for each element in the iterable.
• iterable: the iterable objects you want to traverse.

• The map() function is used to convert the integers in the list to a string.
• The map object is then passed to the join() function.

intList = [1, 2, 3, 4, 5] # The join() and map() functions combine to convert a list of integers to a string result = ', '.join(map(str, intList)) print(result) print(type(result))

Use the index and the str() function.

• Perform access to each index of the list. The indexes to be accessed are of integer type, want it to return a string, and use the str() function to transform.

intList = [1, 2, 3, 4, 5] newStr = '' for index in range(len(intList)): newStr = str(intList[index]) print(newStr) print(type(newStr))

Summary:

The article how to join a list of integers into a string in Python would like to stop here. I hope you found a method that works for you if you don’t have any ideas. Use list comprehension, which is relatively easy to understand and implement. If you have any suggestions or comments about the article, please comment.

My name is Jason Wilson, you can call me Jason. My major is information technology, and I am proficient in C++, Python, and Java. I hope my writings are useful to you while you study programming languages.

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Major: IT
Programming Languages: C++, Python, Java

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Python integer list join

Last updated: Feb 18, 2023
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# Table of Contents

# Join a list of integers into a string in Python

To join a list of integers into a string:

1. Use the map() function to convert the integers in the list to stings.
2. Call the str.join() method on a string separator.
3. Pass the map object to the join() method.

Copied! 
my_list = [1, 2, 3, 4, 5] my_str = ', '.join(map(str, my_list)) print(my_str) # 👉️ "1, 2, 3, 4, 5" 

The str.join method takes an iterable as an argument and returns a string which is the concatenation of the strings in the iterable.

The map() function takes a function and an iterable as arguments and calls the function with each item of the iterable.

Copied! 
my_list = [1, 2, 3, 4, 5] # 👇️ ['1', '2', '3', '4', '5'] print(list(map(str, my_list))) 

We simply passed each integer to the str() class to get a map object that only contains strings.

The string the join() method is called on is used as the separator between elements.

Copied! 
my_list = [1, 2, 3, 4, 5] my_str = '-'.join(map(str, my_list)) print(my_str) # 👉️ "1-2-3-4-5" 

If you don’t need a separator and just want to join the iterable’s elements into a string, call the join() method on an empty string.

Copied! 
my_list = [1, 2, 3, 4, 5] my_str = ''.join(map(str, my_list)) print(my_str) # 👉️ "12345" 

This approach also works if your list contains both strings and integers.

Copied! 
my_list = [1, 'a', 2, 'b', 3, 'c', 4, 'd', 5] my_str = ', '.join(map(str, my_list)) print(my_str) # 👉️ "1, a, 2, b, 3, c, 4, d, 5" 

Alternatively, you can pass a generator expression to the join() method.

# Join a list of integers into a string using a generator expression

This is a three-step process:

1. Call the join() method on a string separator.
2. Pass a generator expression to the join() method.
3. On each iteration, pass the list item to the str() class to convert it to a string.

Copied! 
my_list = [1, 2, 3, 4, 5] result = ', '.join(str(item) for item in my_list) print(result) # 👉️ "1, 2, 3, 4, 5" 

Generator expressions are used to perform some operation for every element or select a subset of elements that meet a condition.

We used a generator expression to convert each item to a string by passing it to the str() class.

# Join a list of integers into a string using a list comprehension

A list comprehension can also be used in place of a generator expression.

Copied! 
my_list = [1, 2, 3, 4, 5] result = ', '.join([str(item) for item in my_list]) print(result) # 👉️ "1, 2, 3, 4, 5" 

The code sample is very similar to the previous one, however, we used a list comprehension.

Copied! 
my_list = [1, 2, 3, 4, 5] list_of_strings = [str(item) for item in my_list] print(list_of_strings) # 👉️ ['1', '2', '3', '4', '5'] print('-'.join(list_of_strings)) # 👉️ 1-2-3-4-5 

On each iteration, we convert the current integer to a string and return the result.

# Join a list of integers into a string using a for loop

A for loop can also be used to convert the list of integers to a list of strings before joining them.

Copied! 
my_list = [1, 2, 3, 4, 5] list_of_strings = [] for item in my_list: list_of_strings.append(str(item)) my_str = ', '.join(list_of_strings) print(my_str) # 👉️ "1, 2, 3, 4, 5" 

We declared a new variable that stores an empty list and used a for loop to iterate over the original list.

On each iteration, we convert the current item to a string and append the result to the new list.

The last step is to join the list of strings with a separator.

# Additional Resources

You can learn more about the related topics by checking out the following tutorials:

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