⭐Summary: The most efficient way to split a string at carriage return (“\r”) 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.
Minimal Example
text = "abc\rpqr\rxyz"
# 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())))
# ['abc', 'pqr', 'xyz']
Problem Formulation
📜Problem: Given a string. How will you split the string at carriage return?
Example
# Input text = "Python\rJava\rGolang" # Output ['Python', 'Java', 'Golang']
📚Highly Recommended Reads:
(i) How to Overwrite the Previous Print to Stdout in Python?
(ii) [FIXED] Carriage return Not Working with Print in VS Code
Method 1: Using split()
The built-in 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 carriage return characters which is also a whitespace character, just by using the split() function.
Code:
text = "Python\rJava\rGolang" print(text.split()) # ['Python', 'Java', 'Golang']
📚Recommended Digest: Python String split()
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: To split the string using carriage return as the delimiter 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 a carriage return character occurs the string will be split.
Code:
import re
text = "Python\rJava\rGolang"
print(re.split('\s+', text))
# ['Python', 'Java', 'Golang']
📚Recommended Read: Python Regex Split.
Method 3: Using re.findall
The 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
Approach: Use the re.findall() method to find all non-whitespace characters and eliminate any empty string using an if condition. All of this can be done with the help of a list comprehension.
Code:
import re text = "Python\rJava\rGolang" print([x for x in re.findall(r'\S+', text) if x != '']) # ['Python', 'Java', 'Golang']
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 'b'.
Approach: Use the re.sub method to replace all occurrences of carraiage return 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.
Code:
import re
text = "Python\rJava\rGolang"
res = re.sub(r'\s+', ',', text).split(',')
print(res)
# ['Python', 'Java', 'Golang']
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Method 5: Using filter
Python’s built-in 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 carraiage return characters. 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 carriage return characters from the given string and returns only the non-whitespace characters. As the filter() method returns an object, we can use the list() constructor to convert the object into a list.
Code:
text = "Python\rJava\rGolang" print(list(filter(None, text.split()))) # ['Python', 'Java', 'Golang']
Conclusion
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]
