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How to remove square brackets from a list using Python

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2023-09-05 19:05:111954browse

How to remove square brackets from a list using Python

Python is a very useful software that can be used for many different purposes depending on the need. Python can be used in web development, data science, machine learning, and many other fields that require automation. It has many different features that help us perform these tasks. Python lists are one of the very useful features of Python. As the name suggests, a list contains all the data you wish to store. It is basically a set of different types of information.

Different ways to remove square brackets

Many times, users will encounter list items displayed in square brackets. In this article, we'll detail how to remove these brackets to get a better view of your listing.

String and replacement functions

One of the easiest ways to remove brackets is to use the Replace() function after creating the list as a string with the help of str() function. This approach makes the code shorter and easier to understand, making the job very simple.

Example

# List Containing Brackets
bracket_list = ["Jack", "Harry", "Sam", "Daniel", "John"]

# We will use str() and replace() to remove the square brackets
modified_list = str(bracket_list).replace('[', '').replace(']', '')

print(modified_list)

Output

The output of this code will look like this:

'Jack', 'harry', 'Sam', 'Daniel', 'John'

List parsing and concatenation

This is another simple method, we first use list comprehension to convert the elements to string and then simply use join() function to remove the brackets. List comprehensions help keep code concise when creating new lists from existing lists. We can understand the use of list comprehensions through the following examples:

Example

# Old list with brackets
old_list = ['A', 'B', 'C', 'D', 'E']

# Removing square brackets using list comprehension and join()
modified_list = ', '.join([str(element) for element in old_list])

print(modified_list)

Output

The output of the above code will be:

A, B, C, D, E  

Mapping functions and connection string functions

In this method of removing brackets from a list, we will simply use the map function to convert the elements to string and then use the join() function to remove the brackets. The map function is typically used to execute a command on each item of a list. We will understand more clearly with the following example:

Example

# Old list with brackets
old_list = [1, 2, 3, 4, 5]

# using map() to create elements into string and str.join() to remove the brackets
modified_list = ', '.join(map(str, old_list))

print(modified_list)

Output

The output of the above code is as follows:

1, 2, 3, 4, 5 

Remove function

This is a very simple method for small lists. In this approach, we first convert the elements to string and then use strip function to remove brackets from the list.

Example

# The old list which contains bracket
old_list = ['P', 'Q', 'R', 'S', 'T']

#The elements are first coverted into tring and then strip() function is given the argument to remove the brackets
modified_list = str(old_list).strip('[]')

print(modified_list)

Output

The output of the above code is as follows:

'P', 'Q', 'R', 'S', 'T'  

Re-module

Re module is used to check whether a specific string matches a pattern. It provides expression functionality to users. In this case, we will use the RE module's re.sub() function to remove the brackets. The re.sub() function is basically used to provide a substitution for a specific element, and in this case, we will use it to replace brackets with empty elements.

Example

import re #We first need to import re module to work with it
#many people forget to import re and due to that reason, there is an error in running the code

# Old list with brackets
old_list = [1, 2, 3, 4, 5]

#Using re.sub() function from re module to replace bracket with empty string
modified_list = re.sub(r'[\[\]]', '', str(old_list))

print(modified_list)

Output

The output of the above code is as follows:

1, 2, 3, 4, 5 

Translation function

This is a complex way to remove brackets from a list of elements. In this method, like all other methods, the element is first converted to a string, but after converting the element to a string, a conversion table is created in which it is specified that the brackets are to be removed. We can understand it more clearly through the following example:

Example

# Old list with brackets
old_list = [1, 2, 3, 4, 5]

# Converting elements into string and then creating a translational table which provides the argument to remove the bracket
modified_list = str(old_list).translate(str.maketrans('', '', '[]'))

print(modified_list)

Output

The output of the above code is as follows:

1, 2, 3, 4, 5 

in conclusion

This article explains different ways to remove brackets from a list. Different methods use different functions to remove the stent. You can use the method of your choice based on your requirements and depending on the complexity of the list. You can use any different functions such as replace function, join function, strip function, map function, re module and translate function. If you want to remove the first and last element, you can also use the slicing functionality by slicing the list and creating a new list without any parentheses.

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