CODEWITHSUNDEEP
pythonstringif-statementinputinteger
Arekusandaa
Arekusandaa

Reputation: 5

How can you make an if statement that checks if input is a str/int

basically im new to python programming and I've just learnt about user input. Im trying to make an if statement that checks if the input is a str or int and then prints a message. If anyone knows how then please comment it, thanks.

print("How old are you?")
dog = input()
final = int(dog) + int(100)

if dog == str:
    print("No")
else:
    print("\nHeres you name + 100!")
    print(f"{final}")
    print("Thanks for playing!")

btw the if statement that I put doesn't work, I dont know if I need to put an exception so it responds with not an error message.

Upvotes: 1

Views: 1897

Answers (2)

tbjorch
tbjorch

Reputation: 1758

Re how to check types, you can do like this:

my_string = "hello"
if isinstance(my_string, str):
    print("I'm a string")
else:
    print("I'm not")

# outputs: "I'm a string"

However, as commented the input method is always returning a value of type str. So if you want to ensure that the value is only consisting of numerical characters, you can use the string method isdigit()

my_string = "asd"
my_string.isdigit() # returns False
my_string = "123"
my_string.isdigit() # returns True

Upvotes: 3

swagless_monk
swagless_monk

Reputation: 471

I would use the type method to check:

print("How old are you?")
dog = input()
final = int(dog) + int(100)

#use type method to check the type of the variable
if type(dog) == str:
    print("No")
else:
    print("\nHeres you name + 100!")
    print(f"{final}")
    print("Thanks for playing!")

Another thing you can do is set prevent the user from entering anything but an int and force a proper variable, something like:

while True:
  dog = input('How old are you? ')
  try:
    dog = int(dog)
    break
  except ValueError:
      print('No')

final = dog + 100
print("\nHeres you name + 100!")
print(f"{final}")
print("Thanks for playing!")

Also, don't waste processing power by converting an int to an int so that means int(100) is the same as 100

Upvotes: 1

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