isidentifier(): checking a valid identifier in Python

Use the isidentifier() method to check a valid identifier.

A valid identifier has only letters, digits, and underscores.

text = 'file1'
print(text.isidentifier())
#output: True

text = '1file'
print(text.isidentifier())
#output: False

text = 'file1_final'
print(text.isidentifier())
#output: True

text = 'file1 final'
print(text.isidentifier())
#output: False

Notice that an identifier must not start with a number or have spaces.