what are python identifiers with example

what are python identifiers with example : 

An identifier is a simple concept which is used to identify entities. ( i.e. class, variables,  functions,module or other object ) Identifier used to differentiate one entity from another entityAn identifier starts with an underscore (_), letter A to Z or small letter a to z or  simply follow by zero or more letter and digits (0 to 9).

Python identifier simple example :

what are python identifiers
what are python identifiers

In the following example we have to used three variables. 
The name of the variables
  •  rollno.,
  •  _sachin
  • and sachin_samprada are the identifiers.
# Basic examples on identifiers

rollno = 1
print(rollno)

_sachin = 5
print(_x)

sachin_samprada = 143
print(sachin_samprada)
OUTPUT :
>> 1
>> 5
>>  143

Rules to Create Python Identifiers :

There are different no. of rules that must need to be followed to create a python identifier.
  • An identifier starts with an underscore (_), letter A to Z or small letter a to z or  simply follow by zero or more letter and digits (0 to 9)
  • sachin_SAMPRADA : contains all the valid character
  • _: underscore is also valid identifier
  • _sachin: it is valid to identifier can start with an underscore symbol 
Some python Invalid Identifiers Example :
  • 143: identifier cannot be only digit
  • 143samprada: identifier cannot start with number
  • sachin+samprada: the only special character is valid an underscore
  • from: it is a reserved keyword
How to check if a String is a Valid Identifier in python? :
  • Identifier name cannot begin with a digit or number.
  • Python identifier cannot contain only digits or number.
  •  Identifier name can start with an underscore is valid.
  • There is no any limit on the length of the identifier.
  • Identifier name are case sensitive in nature.
  • sachin143samprada: Identifier contain only letters and numbers
We can use python string identifier() Functions to check identifier name is valid or not. But, this method doesn’t take reserved keywords into consideration. So, we can use this function with keyword.iskeyword() to check if the name is valid or not.
print("_".fallinlove()) # True
print("for".inlove()) # True - wrong output(error)
print("sahin".inlove())  # True
print("143sach".isidentifier())  # False

list of the Python keywords :

...
help> keywords

Here is a list of the Python keywords.  Enter any keyword to get more help.

False               def                 if                  raise
None                del                 import              return
True                elif                in                  try
and                 else                is                  while
as                  except              lambda              with
assert              finally             nonlocal            yield
break               for                 not                 
class               from                or                  
continue            global              pass
Things to must Remember :
  • Multiple set of word can be separated using an underscore, like (fall_in_love)
  •  variable and variable later are not the same(i.e.Python is a case-sensitive language)
some FAQ about python identifier :

What are valid identifiers in Python?
Identifiers can be combination of different things like lowercase and uppercase letters, underscore(_) or an digits. So test_1, test_for_print all are valid python identifiers

What are variables and identifiers in Python?
Variable is a name that is used to show many things like object, person etc. Python variable is python identifier and used to hold value.

What are the basic elements of Python?
tuples (simple sequences),strings (text), numbers (integers and floating point numbers), dictionaries and lists (more flexible sequences), .

SUMMARY : In this article we saw the different concept in identifiers in Python so any question about this article then comment please, I'm ready to solve it.
Tags: What are valid identifiers in Python?,What are variables and identifiers in Python?,What are the basic elements of Python?
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