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Python program to check whether a variable is a string or not
Python | Check if a variable is a string: Here, we are going to learn how to check whether a given variable is a string type or not in Python programming language?
By IncludeHelp Last updated : February 25, 2024
Python | Check if a variable is a string
To check whether a defined variable is a string type or not, we can use two functions which are Python library functions,
- Using isinstance()
- Using type()
Checking a variable is a string or not using isinstance() function
isinstance() function accepts two parameters – 1) variable name (object) and 2) data type (class) and returns whether an object is an instance of a class or of a subclass thereof.
Syntax
isinstance(obj, class_or_tuple)
Example
# variables
a = 100 # an integer variable
b = 10.23 # a float variable
c = 'A' # a character variable
d = 'Hello' # a string variable
e = "Hello" # a string variable
# checking types
if isinstance(a, str):
print("Variable \'a\' is a type of string.")
else:
print("Variable \'a\' is not a type of string.")
if isinstance(b, str):
print("Variable \'b\' is a type of string.")
else:
print("Variable \'b\' is not a type of string.")
if isinstance(c, str):
print("Variable \'c\' is a type of string.")
else:
print("Variable \'c\' is not a type of string.")
if isinstance(d, str):
print("Variable \'d\' is a type of string.")
else:
print("Variable \'d\' is not a type of string.")
if isinstance(e, str):
print("Variable \'e\' is a type of string.")
else:
print("Variable \'e\' is not a type of string.")
Output
Variable 'a' is not a type of string.
Variable 'b' is not a type of string.
Variable 'c' is a type of string.
Variable 'd' is a type of string.
Variable 'e' is a type of string.
Checking a variable is string using type() function
type() function accepts one parameter (others are optional), and returns its type.
Syntax
type(object)
Example
# variables
a = 100 # an integer variable
b = 10.23 # a float variable
c = 'A' # a character variable
d = 'Hello' # a string variable
e = "Hello" # a string variable
# checking types
if type(a) == str:
print("Variable \'a\' is a type of string.")
else:
print("Variable \'a\' is not a type of string.")
if type(b) == str:
print("Variable \'b\' is a type of string.")
else:
print("Variable \'b\' is not a type of string.")
if type(c) == str:
print("Variable \'c\' is a type of string.")
else:
print("Variable \'c\' is not a type of string.")
if type(d) == str:
print("Variable \'d\' is a type of string.")
else:
print("Variable \'d\' is not a type of string.")
if type(e) == str:
print("Variable \'e\' is a type of string.")
else:
print("Variable \'e\' is not a type of string.")
Output
Variable 'a' is not a type of string.
Variable 'b' is not a type of string.
Variable 'c' is a type of string.
Variable 'd' is a type of string.
Variable 'e' is a type of string.
To understand the above programs, you should have the basic knowledge of the following Python topics:
Python String Programs »