How to check if any of the multiple strings are not present in a string in Python [duplicate]

Question

I have a String message

message = "The boy Akash is studying in 9th class at Boys school"

I wanted to check if any of the words boy or class or school is not present. If any of those are not present it should show a error message.

if('boy' or 'class' or 'school' not in message):
    print = "Please check if you have filled all data"

But when I tried this, even if all keywords are present its showing error. Where it could be wrong.

Answer 1

It doesn't work because what you wrote is not what you meant.

Consider the snippet:

if 'boy':
    print("There's a boy here")

If you run it, you'll get:

>>> There's a boy here!

This is because by default, python consider all non-empty string as True.

Therefore, to fix your code, you need to:

if('boy' not in message or 'class' not in message or 'school' not in message):
    print = "Please check if you have filled all data"

or, equivalently:

for word in ['boy', 'class', 'school']:
    if word not in message:
        print = "Please check if you have filled all data"

Answer 2

Presumably you have to list out each expression separately:

if "boy" not in message or "class" not in message or "school" not in message:
    print = "Please check if you have filled all data"

You could also use regex here, which would allow you to use word boundaries, for a possibly more reliable match:

match1 = re.search(r'\bboy\b', message)
match2 = re.search(r'\bclass\b', message)
match3 = re.search(r'\bschool\b', message)
if not match1 or not match2 or not match3:
    print = "Please check if you have filled all data"

Answer 3

What is your error?

Your syntax should be:

if ('boy' not in message) or ('class' not in message) or ('school' not in message) :
    print("Please check if you have filled all data") 

If you have a conditional with multiple expressions, you must give each expression separated by a logical operator (or, and) , as above but also for more complex decision structures eg:

if ( (x < 2) and (y > 5) ) or (z == 0):
    print("") 

Note the print statement - you have tried to assign a string to a variable print as opposed to using the print function with a string as argument. As the print keyword is reserved as a standard library function, you shouldn't be able to use it as a variable.