Checks for alphanumeric characters in a string. Returns True if only number and alphabets are present and returns False if any thing other than alphanumeric characters are present.
my_str='plus2net'
print(my_str.isalnum()) # Output is True
my_str='Welcome to plus2net'
print(my_str.isalnum()) # Output is False (presence of Space)
More using special chars
print('plus2net'.isalnum()) # True 2 is allowed
print('_plus2net'.isalnum()) #False _ not allowed
print('plus_2net'.isalnum()) #False _ not allowed
print('plus.2net'.isalnum()) #False . not allowed
print('plus-2net'.isalnum()) #False - not allowed
print('plus@2net'.isalnum()) #False @ not allowed
print('plus#2net'.isalnum()) #False # not allowed
print('plus 2net'.isalnum()) #False space not allowed