Remove Whitespaces from Strings in Python

Using string methods and regexes in Python

How to remove whitespaces in a string in python

str.lstrip()
str.rstrip()
str.strip()
str.replace()
str.split()
re.sub()

By using the above-mentioned methods, let’s see how to remove whitespaces in a string.

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1. Removing leading whitespaces in a string

1. str.lstrip()
Return a copy of the string with leading whitespaces removed.

s="   Hello   Python  "
print (s.lstrip())
#Output:Hello   Python

2. re.sub()
Using re.sub(), we can remove leading whitespaces.

Syntax:

re.sub(pattern, repl, string, count=0, flags=0)

pattern – specify the pattern to be replaced
repl – replacing the leftmost non-overlapping occurrences of pattern in string by the replacement repl.
count – The optional argument count is the maximum number of pattern occurrences to be replaced. If omitted or zero, all occurrences will be replaced.

pattern= r”^s+”

r Python’s raw string notation for regular expression
s matches whitespace characters.
+ It will match one or more repetitions of whitespace character.
^(Caret.) Matches the start of the string

pattern mentioned is whitespace at the beginning of the string.
s1=re.sub(pattern,””,s)

re.sub() will replace the pattern (whitespaces at the beginning of string) to empty string.

s="   Hello   Python  "
import re
pattern= r"^s+"
s1=re.sub(pattern,"",s)
print (s1)#Output:Hello   Python

2. Removing trailing whitespace in a string

str.rstrip()

Return a copy of the string with trailing whitespaces removed.

s="   Hello   Python  "
print (s.rstrip())
#Output:   Hello   Python

re.sub()
Using re.sub(), we can remove trailing whitespaces.

pattern= r"s+$"

r-Python’s raw string notation for regular expression
s — matches whitespace characters.
+ It will match one or more repetitions of whitespace character.
$ Matches the end of the string

pattern mentioned are whitespaces at the end of the string.
s1=re.sub(pattern,””,s)

re.sub() will replace the pattern (whitespaces at the end of the string) to empty string.

s="   Hello   Python  "
import re
pattern= r"s+$"
s1=re.sub(pattern,"",s)
print (s1)#Output:Hello   Python

3. Removing leading and trailing whitespace in a string

str.strip()

Return the copy of the string with leading whitespaces and trailing whitespaces removed.

s="   Hello   Python  "
print(s.strip())
#Output:Hello   Python

re.sub()

Using re.sub(), we can remove leading whitespaces and trailing whitespaces.
pattern="^s+|s+$"

^s+ Matches one or more whitespaces at the beginning of the string

s+$ Matches one or more whitespaces at the end of the string.

| x|y matches either x or y

s="   Hello   Python  "
import re
pattern="^s+|s+$"
s1 = re.sub(pattern, "",s)
print(s1)
#Output:Hello   Python

4. Remove all whitespaces in a string.

str.replace()
Return a copy of the string with all occurrences of substring old replaced by new.

Syntax:

str.replace(old,new,count)

print (s.replace(" ",""))

It will replace all whitespace characters into an empty string.

s="   Hello   Python   "
print (s.replace(" ",""))
#Output:HelloPython

re.sub()
Using re.sub(), we can remove all whitespaces in the string.

pattern=r"s+"
s1 = re.sub(pattern, "", s)

pattern matches all whitespaces in the string.
Then re.sub(), replacing pattern(whitespaces ) to empty string.

s="   Hello   Python   "
import re
pattern=r"s+"
s1 = re.sub(pattern, "", s)
print (s1)
#Output:HelloPython

str.split()
Returns list of all words in the string separated using delimiter string. If the delimiter is not mentioned, by default whitespace is the delimiter.

join() — join () method takes all items in the iterable and combines them into a string using a separator

s1="".join(s.split())

Splitting the string and joining the elements using an empty string

s="   Hello   Python   "
print (s.split())#Output:['Hello', 'Python']
#joining the elements in the string using empty string.
s1="".join(s.split())
print (s1)#Output:HelloPython

5. Removing duplicate whitespaces in the string

str.split()
Returns list of all words in the string separated using delimiter string. If the delimiter is not mentioned, by default whitespace is the delimiter.

join() — join () method takes all items in the iterable and combines them into a string using a separator

s1=" ".join(s.split())

Splitting the string and joining the elements using a single whitespace string

s="Hello      Python"
print (s.split())#Output:['Hello', 'Python']
#joining the elements in the string using single whitespace string.
s1=" ".join(s.split())
print (s1)#Output:Hello Python