Python - Print list without spaces

Python - Print list without spaces

When you print a list to console output in Python, spaces appear along with comma separator between the elements in the list.

To print list without spaces in Python, write a custom function that takes a list as argument, joins all the elements in the list with just a comma character as separator between the elements, and enclose the resulting string in square brackets.

For example, consider the following list.

x = ['apple', 'banana', 100, 200]

When you print this list to output using print() built-in function, you would get the following output.

['apple', 'banana', 100, 200]

But, our requirement is that there should not be any spaces between the elements in the list.

['apple','banana',100,200]

Just the spaces after comma between the elements removed from the string representation of the list. Rest all same.

Steps to print list without spaces in Python

The following is a step by step process to print the given list without spaces in Python. Also, intermediate results have been given after the code, so that we understand what is happening with an example.

1. Given a list in x.

x = ['apple', 'banana', 100, 200]

2. Use list comprehension and convert each of the element in the list to a string.

[str(item) for item in x]

['apple', 'banana', '100', '200']

3. We have to modify this list comprehension to surround the string elements with single quotes. Place single quotes around the string if the element is an instance of str class, or else just the item.

[f"'{item}'" if isinstance(item, str) else str(item) for item in x]

['\'apple\'', '\'banana\'', '100', '200']

This step is to preserve the quotes surrounding the string elements in the list when printed to output.

4. Join the elements of the above list with comma character as separator using string join() method, and concatenate opening and closing square brackets surrounding the string using string concatenation.

"[" + ",".join(items_str) + "]"

['apple','banana',100,200]

5. You may print this string to output using print() built-in function.

Program

The complete program to print the given list without spaces between the elements to standard output is given below.

In the following program, print_list_without_spaces() function takes a list and prints the list without commas.

Python Program

# Custom function to print list without spaces
def print_list_without_spaces(x):
    items_str = [f"'{item}'" if isinstance(item, str) else str(item) for item in x]
    print("[" + ",".join(items_str) + "]")

# Given a list of strings
my_list = ['apple', 'banana', 100, 200]

print_list_without_spaces(my_list)

Output

['apple','banana',100,200]

There you have it. The list has been printed to console output without spaces between the elements.

Summary

In this tutorial, we have seen how to print a given list without spaces between the elements, to standard output, using str() built-in function, list comprehension with if else, string join() method, string concatenation, and print() built-in function, with an example program.