Python string isidentifier() usage and example

Python string methods

If the string is a valid identifier in Python, the isidentifier() method returns True. If not, it returns False.

The syntax of isidentifier() is:

string.isidentifier()

isidentifier() parameters

The isidentifier() method does not take any parameters.

isidentifier() return value

The isidentifier() method returns:

• True if the string is a valid identifier

• False if the string is not a valid identifier

Example1: How does isidentifier() work?

str = 'Python'
print(str.isidentifier())
str = 'Py　thon'
print(str.isidentifier())
str = ''22Python
print(str.isidentifier())
str = ''
print(str.isidentifier())

When running the program, the output is:

True
False
False
False

Visit this page to learnWhat is a valid identifier in Python?

Example2: More examples of isidentifier()

str = 'root33'
if str.isidentifier() == True:
　　print(str, 'is a valid identifier.')
else:
　　print(str, 'is not a valid identifier.')
　　
str = ''33root'
if str.isidentifier() == True:
　　print(str, 'is a valid identifier.')
else:
　　print(str, 'is not a valid identifier.')
　　
str = 'root　33'
if str.isidentifier() == True:
　　print(str, 'is a valid identifier.')
else:
　　print(str, 'is not a valid identifier.')

When running the program, the output is:

root33　Is a valid identifier.
33root is not a valid identifier.
root　33　Is not a valid identifier.

Python string methods