Summary: Use Python’s built-in split function to split a given string into a list substrings. Other methods include using the regex library and the map function.

Minimal Example

text = "Python Java Golang" # Method 1

print(text.split()) # Method 2

import re

print(re.split('\s+',text)) # Method 2.1

print(re.findall('\S+', text)) # Method 3

li = list(map(str.strip, text.split()))

res = []

for i in li: for j in i.split(): res.append(j)

print(res) # OUTPUTS: ['Python', 'Java', 'Golang']

Problem Formulation

Problem: Given a string containing numerous substrings. How will you split the string into a list of substrings?

Let’s understand the problem with the help of an example.

Example

# Input

text = "word1 word2 word3 word4 word5" # Output

['word1', 'word2', 'word3', 'word4', 'word5']

Method 1: Using strip

Approach: Use the split("sep") function where sep is the specified separator. In our case the separator is a space. Hence, you do not need to pass any separator to the function as whitespaces are considered to be default separators for the split function. Therefore, whenever a space occurs the string will be split and the substring will be stored in a list.

Code:

text = "word1 word2 word3 word4 word5"

print(text.split()) # ['word1', 'word2', 'word3', 'word4', 'word5']

Method 2: Using re.split

The re.split(pattern, string) method matches all occurrences of the pattern in the string and divides the string along the matches resulting in a list of strings between the matches. For example, re.split('a', 'bbabbbab') results in the list of strings ['bb', 'bbb', 'b'].

Approach: Use thr re.split('\s+',text) method, where text is the given string and ‘\s+‘ returns a match whenever it finds a space in the string.Therefore, on every occurrence of a space the string will be split.

Code:

import re text = "word1 word2 word3 word4 word5"

print(re.split('\s+',text)) # ['word1', 'word2', 'word3', 'word4', 'word5']

Related Read: Python Regex Split

Method 3: Using re.findall

The re.findall(pattern, string) method scans string from left to right, searching for all non-overlapping matches of the pattern. It returns a list of strings in the matching order when scanning the string from left to right.

Related Read: Python re.findall() – Everything You Need to Know

Approach: Use thr re.findall('\S+',text) method, where text is the given string and ‘\S+‘ returns a match whenever it finds a normal character in the string except whitespace. Therefore, all the non-whitespace characters will be grouped together until the script encounters a space. On the occurrence of a space, the string will be split and the next group of characters that do not include a space will be searched.

Code:

import re text = "word1 word2 word3 word4 word5"

print(re.findall('\S+', text)) # ['word1', 'word2', 'word3', 'word4', 'word5']

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Method 4: Using map

Prerequisite: The map() function transforms one or more iterables into a new one by applying a “transformator function” to the i-th elements of each iterable. The arguments are the transformator function object and one or more iterables. If you pass n iterables as arguments, the transformator function must be an n-ary function taking n input arguments. The return value is an iterable map object of transformed, and possibly aggregated, elements.

Related Read: Python map() — Finally Mastering the Python Map Function [+Video]

Approach: Use the map function such that the iterable is the split list of substrings. This is the second argument of the map method. Now each item of this list will be passed to the strip method which eliminates the trailing spaces if any and then returns a map object containing the split substrings. You can convert this map object to a list using the list constructor.

Code:

text = "word1 word2 word3 word4 word5"

li = list(map(str.strip, text.split()))

res = []

for i in li: for j in i.split(): res.append(j)

print(res) # ['word1', 'word2', 'word3', 'word4', 'word5']

Exercise

Problem: Given a string containing numerous substrings separated by commas and spaces. How will you extract the substrings and store them in a list? Note that you have to eliminate the whitespaces as well as the commas.

# Input

text = "One, Two, Three"

# Output

['One', 'Two', 'Three']

Hint: Python | Split String by Comma and Whitespace

Solution:

text = "One, Two, Three"

print([x.strip() for x in text.split(',')])

# ['One', 'Two', 'Three']

Conclusion

With that, we come to the end of this tutorial. I hope the methods discussed in this article have helped you and answered your queries. Please stay tuned and subscribe for more solutions and discussions in the future.

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Summary: maxsplit is one of the optional parameters used in the split() function. If maxsplit is specified within the split function, then the maximum number of splits done will be given by the specified maxsplit. Thus, the list will have at most maxsplit + 1 elements. If maxsplit is not specified or set to -1, then there is no limit on the number of splits (all the possible splits are made).

Minimal Example

cols = 'Red, Black, White, Yellow, Pink' # Maxsplit 0

print(cols.split(', ', 0))

# ['Red, Black, White, Yellow, Pink'] # Maxsplit 1

print(cols.split(', ', 1))

# ['Red', 'Black, White, Yellow, Pink'] # Maxsplit 3

print(cols.split(', ', 3))

# ['Red', 'Black', 'White', 'Yellow, Pink'] # Maxsplit 5

print(cols.split(', ', 5))

# ['Red', 'Black', 'White', 'Yellow', 'Pink']

In this comprehensive guide, you will learn everything you need to know about maxsplit in Python.

What is Maxsplit Anyways?

Before you understand what maxsplit does, it is important to understand what the split function does. The split() function in Python splits the string at a given separator and returns a split list of substrings.

Syntax and Explanation:
str.split(sep = None, maxsplit = -1)

maxsplit is an optional parameter that defines the maximum number of splits (the list will have at most maxsplit + 1 elements). If maxsplit is not provided or defined as -1, then there is no limit on the number of splits (all the possible splits get made).

Related Read: Python String split()

How Many Elements will The List Contain when Maxsplit is Specified?

When the maxsplit is specified, the list will have a maximum of maxsplit + 1 items. Look at the following examples to understand this better.

text = 'Python Java C Ruby' # Example 1

print(text.split(' ', 0))

# ['Python Java C Ruby'] # Example 2

print(text.split(' ', 2))

# ['Python', 'Java', 'C Ruby'] # Example 3

print(text.split(' ', -1))

# ['Python', 'Java', 'C', 'Ruby']

Explanation: In the first example, the maxsplit gets set to 0. Hence the list will have a maximum of one item. In the second example, maxsplit is set to 2, therefore the resultant list will have 2+1 = 3 items. Note that in the third example, maxsplit gets specified as -1; hence by default all the possible splits have been made.

Will the split() Function Work if You Don’t Specify Any Parameter?

Example:

txt = 'Welcome to the world of Python'

print(txt.split())

# ['Welcome', 'to', 'the', 'world', 'of', 'Python']

The split() function works perfectly fine even when no arguments are specified. In the above example, no separator and no maxsplit has been specified. It takes the default separator (space) to split the string. By default, the maxsplit value is -1. So the string gets split wherever a space is found. Meaning the maximum number of splits will be performed.

Split a List up to a Maximum Number of Elements

Problem:  Given a list; How will you split the list up to a maximum number of elements?

Example: Let’s visualize the problem with a real problem asked in StackOverflow.

Discussion: The question essentially requires you to split the first and the second item/row into 7 columns such that the expected output resembles the following: [['6697', '1100.0', '90.0', '0.0', '0.0', '6609', '!'], ['701', '0.0', '0.0', '83.9', '1.5', '000', '!AFR-AHS IndHS-AFR']]

Solution:

rot = ['6697 1100.0 90.0 0.0 0.0 6609 !', '701 0.0 0.0 83.9 1.5 000 !AFR-AHS IndHS-AFR'] for i in range(len(rot)): rot[i] = rot[i].split(maxsplit=6) print(rot) # [['6697', '1100.0', '90.0', '0.0', '0.0', '6609', '!'], ['701', '0.0', '0.0', '83.9', '1.5', '000', '!AFR-AHS IndHS-AFR']]

Explanation: Use the split() method and specify the maxsplit argument as the maximum number of elements in the list that you want to group. In this case, you need seven splits. Hence, the maxsplit can be set to 6 to achieve the final output.

Exercise

Given:
text = “abc_kjh_olp_xyz”
Challenge: Split the given string only at the first occurrence of the underscore “_”
Expected Output:
[‘abc’, ‘kjh_olp_xyz’]

Solution

text = "abc_kjh_olp_xyz"

print(text.split("_", maxsplit=1))

Related Read: Python Split String at First Occurrence

Conclusion

That was all about the maxsplit parameter from the split() function in Python. I hope this article helped you to gain an in-depth insight into the maxsplit parameter. Please subscribe and stay tuned for more interesting articles! Happy coding.

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