How to check if a string is a valid keyword in Python?

1

Defining a Keyword

In programming, a keyword is a “reserved word” by the language which convey a special meaning to the interpreter. It may be a command or a parameter. Keywords cannot be used as a variable name in the program snippet.

Keywords in Python:  Python language also reserves some of keywords that convey special meaning. Knowledge of these is necessary part of learning this language. Below is list of keywords registered by python .

Keyword
How to check if a string is keyword?

Python in its language defines an inbuilt module “keyword” which handles certain operations related to keywords. A function “iskeyword()” checks if a string is keyword or not. Returns true if a string is keyword, else returns false.


#Python code to demonstrate working of iskeyword()

# importing "keyword" for keyword operations
import keyword

# initializing strings for testing
s = "for"
s1 = "geeksforgeeks"
s2 = "elif"
s3 = "elseif"
s4 = "nikhil"
s5 = "assert"
s6 = "shambhavi"
s7 = "True"
s8 = "False"
s9 = "akshat"
s10 = "akash"
s11 = "break"
s12 = "ashty"
s13 = "lambda"
s14 = "suman"
s15 = "try"
s16 = "vaishnavi"

# checking which are keywords
if keyword.iskeyword(s):
        print ( s + " is a python keyword")
else :  print ( s + " is not a python keyword")

if keyword.iskeyword(s1):
        print ( s1 + " is a python keyword")
else :  print ( s1 + " is not a python keyword")

if keyword.iskeyword(s2):
        print ( s2 + " is a python keyword")
else :  print ( s2 + " is not a python keyword")

if keyword.iskeyword(s3):
        print ( s3 + " is a python keyword")
else :  print ( s3 + " is not a python keyword")

if keyword.iskeyword(s4):
        print ( s4 + " is a python keyword")
else :  print ( s4 + " is not a python keyword")

if keyword.iskeyword(s5):
        print ( s5 + " is a python keyword")
else :  print ( s5 + " is not a python keyword")

if keyword.iskeyword(s6):
        print ( s6 + " is a python keyword")
else :  print ( s6 + " is not a python keyword")

if keyword.iskeyword(s7):
        print ( s7 + " is a python keyword")
else :  print ( s7 + " is not a python keyword")

if keyword.iskeyword(s8):
        print ( s8 + " is a python keyword")
else :  print ( s8 + " is not a python keyword")

if keyword.iskeyword(s9):
        print ( s9 + " is a python keyword")
else :  print ( s9 + " is not a python keyword")

if keyword.iskeyword(s10):
        print ( s10 + " is a python keyword")
else :  print ( s10 + " is not a python keyword")

if keyword.iskeyword(s11):
        print ( s11 + " is a python keyword")
else :  print ( s11 + " is not a python keyword")

if keyword.iskeyword(s12):
        print ( s12 + " is a python keyword")
else :  print ( s12 + " is not a python keyword")

if keyword.iskeyword(s13):
        print ( s13 + " is a python keyword")
else :  print ( s13 + " is not a python keyword")

if keyword.iskeyword(s14):
        print ( s14 + " is a python keyword")
else :  print ( s14 + " is not a python keyword")

if keyword.iskeyword(s15):
        print ( s15 + " is a python keyword")
else :  print ( s15 + " is not a python keyword")

if keyword.iskeyword(s16):
        print ( s16 + " is a python keyword")
else :  print ( s16 + " is not a python keyword")

Output:

for is a python keyword
geeksforgeeks is not a python keyword
elif is a python keyword
elseif is not a python keyword
nikhil is not a python keyword
assert is a python keyword
shambhavi is not a python keyword
True is a python keyword
False is a python keyword
akshat is not a python keyword
akash is not a python keyword
break is a python keyword
ashty is not a python keyword
lambda is a python keyword
suman is not a python keyword
try is a python keyword
vaishnavi is not a python keyword

How to print list of all keywords

Sometimes, remembering all the keywords can be a difficult task while assigning variable names. Hence a function “kwlist()” is provided in “keyword” module which prints all the 33 python keywords.

#Python code to demonstrate working of iskeyword()

# importing "keyword" for keyword operations
import keyword

# printing all keywords at once using "kwlist()"
print ("The list of keywords is : ")
print (keyword.kwlist)

Output:

The list of keywords is : 
['False', 'None', 'True', 'and', 'as', 'assert', 'break', 'class', 
'continue', 'def', 'del', 'elif', 'else', 'except', 'finally', 
'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 
'nonlocal', 'not', 'or', 'pass', 'raise', 'return', 
'try', 'while', 'with', 'yield']

 
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