Python：TypeError：“ str”对象无法通过if语句调用

Question

I've read over 50 posts with similar 'title' and have yet to answer my question.

If this question is a duplicate please link the [SOLVED] post. Using Python 2.7.7

count = 0
playerChoice = str(raw_input("What do you do this turn? "))

if playerChoice() == 'r':
    count = count + 1
    print "Added one bullet. ", count

Error it gives is:

if playerChoice() == 'r':
TypeError: 'str' object is not callable

To my understanding my code does this:

If the player enters str('r'). Count will add one and the print statement should print: "Added one bullet." However, when you enter 'r' in the raw_input. It gives an error. Why is that? I tried adding %s to the raw_input (I read it on another post), however that did not do a thing.

Help would be appreciated thank you.

Answer 1

playerChoice will evaluate to a string. So calling it later with playerChoice() , ( adding the () at the end calls the variable ), throws an error because a string cant be called like a function can.

Use playerChoice to evaluate the string instead:

playerChoice = raw_input("What do you do this turn? ")

if playerChoice == 'r':
    count += 1
    print "Added one bullet. ", count

Answer 2

if playerChoice() == 'r': should be if playerChoice == 'r': minus the ()

You don't call a string, it is not a function.

Also raw_input("What do you do this turn? ") is already a string no need to cast

If you wanted an int :

you would have to cast int(raw_input("What do you do this turn? ")) but not for strings.

Answer 3

playerChoice is a variable, not a function. Use:

if playerChoice == 'r':

rather than playerChoice() .

Answer 4

Since playerChoice is a variable and not a reference to a function call, you will not need parentheses to use playerChoice. If you use playerChoice() , interpreter will try to invoke a method, and will get failed because playerChoice is not referring to a function call.

Thing here to understand is that str(raw_input("What do you do this turn? ")) returns a string, not a function. therefore you will not need to use parentheses.