Thursday, August 28, 2025
HomeLanguagesCheck if a variable is string in Python

Check if a variable is string in Python

While working with different datatypes, we might come across a time, when we need to test the datatype for its nature. This article gives ways to test a variable against the data type using Python. Let’s discuss certain ways how to check variable is a string.

Check if a variable is a string using isinstance() 

This isinstance(x, str) method can be used to test whether any variable is a particular datatype. By giving the second argument as “str”, we can check if the variable we pass is a string or not. 

Python3




# initializing string
test_string = "GFG"
 
# printing original string
print("The original string : " + str(test_string))
 
# using isinstance()
# Check if variable is string
res = isinstance(test_string, str)
 
# print result
print("Is variable a string ? : " + str(res))


Output:

The original string : GFG
Is variable a string ? : True

Check if a variable is a string using type() 

This task can also be achieved using the type function in which we just need to pass the variable and equate it with a particular type. 

Python3




# initializing string
test_string = "GFG"
 
# printing original string
print("The original string : " + str(test_string))
 
# using type()
# Check if variable is string
res = type(test_string) == str
 
# print result
print("Is variable a string ? : " + str(res))


Output:

The original string : GFG
Is variable a string ? : True

Method 3 : using the issubclass() method.

step-by-step approach

Initialize the variable test_string with a string value.
Print the original string using the print() method.
Check if the variable is a string using the issubclass() method with the following parameters: the type() of the variable and the str class.
Assign the result to a variable called res.
Print the result using the print() method.

Python3




# initializing string
test_string = "GFG"
 
# printing original string
print("The original string : " + str(test_string))
 
# using issubclass()
# Check if variable is string
res = issubclass(type(test_string), str)
 
# print result
print("Is variable a string ? : " + str(res))


Output

The original string : GFG
Is variable a string ? : True

The time complexity of both methods is O(1), and the auxiliary space required is also O(1) since we are only creating a single variable res to store the result.

RELATED ARTICLES

Most Popular

Dominic
32236 POSTS0 COMMENTS
Milvus
80 POSTS0 COMMENTS
Nango Kala
6609 POSTS0 COMMENTS
Nicole Veronica
11779 POSTS0 COMMENTS
Nokonwaba Nkukhwana
11828 POSTS0 COMMENTS
Shaida Kate Naidoo
6719 POSTS0 COMMENTS
Ted Musemwa
7002 POSTS0 COMMENTS
Thapelo Manthata
6678 POSTS0 COMMENTS
Umr Jansen
6690 POSTS0 COMMENTS