⭐Summary: The most efficient way to split a string using variable spaces is to use the
split function like so
given_string.split(). An alternate approach is to use different functions of the regex package to split the string at multiple whitespaces.
text = "a b c d" # Method 1 print(text.split()) # Method 2 import re print(re.split('\s+', text)) # Method 3 print([x for x in re.findall(r'\S+', text) if x != '']) # Method 4 print(re.sub(r'\s+', ',', text).split(',')) # Method 5 print(list(filter(None, text.split()))) # ['a', 'b', 'c', 'd']
📜Problem: Given a string. How will you split the string using multiple spaces?
# Input text = "abc xyz lmn pqr" # Output ['abc', 'xyz', 'lmn', 'pqr']
The given input has multiple spaces between each substring, i.e., there are three spaces after
abc, two spaces after
xyz while a single space after
lmn. So, not only do you have multiple spaces between the substring but also varied number of spaces. Can you split the string by varied and multiple spaces?
Though the question might look daunting at first but once you get hold of it, the solutions to this problem are easier than one can imagine. So, without further delay let us dive into the different ways of solving the given problem.
Method 1: Using split()
split('sep') function allows you to split a string in Python based on a given delimiter. By default the
split function splits a given string at whitespaces. Meaning, if you do not pass any delimiter to the split function then the string will be split at whitespaces.
You can use this default property of the split function and successfully split the given string at multiple spaces just by using the
text = "abc xyz lmn pqr" print(text.split()) # ['abc', 'xyz', 'lmn', 'pqr']
📚Recommended Digest: Python String split()
Method 2: Using re.split
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: To split the string using multiple space characters use
re.split("\s+", text) where
\s+ is the matching pattern and it represents a special sequence that returns a match whenever it finds any whitespace character and splits the string. So, whenever there’s a space or multiple spaces (any number of occurrences of space are whitespace characters) the string will be split.
import re text = "abc xyz lmn pqr" print(re.split('\s+', text)) # ['abc', 'xyz', 'lmn', 'pqr']
📚Recommended Read: Python Regex Split.
Method 3: Using re.findall
re.findall(pattern, string) method scans the
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.
📚Recommended Read: Python re.findall() – Everything You Need to Know
import re text = "abc xyz lmn pqr" print([x for x in re.findall(r'\S+', text) if x != '']) # ['abc', 'xyz', 'lmn', 'pqr']
Method 4: Using re.sub
The regex function
re.sub(P, R, S) replaces all occurrences of the pattern
P with the replacement
R in string
S. It returns a new string. For example, if you call
re.sub('a', 'b', 'aabb'), the result will be the new string
'bbbb' with all characters
'a' replaced by
Approach: Use the
re.sub method to replace all occurrences of space characters in the given string with a comma. Thus, the string will now have commas instead of space characters and you can simply split it using a normal string split method by passing comma as the delimiter.
Silly! Isn’t it? Nevertheless, it works.
import re text = "abc xyz lmn pqr" res = re.sub(r'\s+', ',', text).split(',') print(res) # ['abc', 'xyz', 'lmn', 'pqr']
Method 5: Using filter
filter() function filters out the elements that pass a filtering condition. It takes two arguments: function and iterable. The function assigns a Boolean value to each element in the iterable to check whether the element will pass the filter or not. It returns an iterator with the elements that pass the filtering condition.
📚Related Read: Python filter()
Approach: You can use the
filter() method to split the string by space. Feed in
None as the first argument and the list of split strings as the second argument into the
filter function. The
filter() function then iterates through the list and filters out the spaces from the given string and returns only the non-whitespace characters. As the
filter() method returns an object, we need to use the
list() constructor to convert the object into a list.
text = "abc xyz lmn pqr" print(list(filter(None, text.split()))) # ['abc', 'xyz', 'lmn', 'pqr']
Hurrah! We have successfully solved the given problem using as many as five different ways. I hope you enjoyed reading this article and it helped you in your Python coding journey. Please subscribe and stay tuned for more interesting articles!
Happy coding! 🙂
📚Suggested Read: Python Regex Superpower [Full Tutorial]
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