TypeError: Missing one required positional argument

问题

I am working on a game as a side project for fun and I have run into this error and I really don't know why it is happening...

Here is the code:

class players:
    def __init__(self, location, image_file, direction):
        self.location = location
        self.image_file = image_file
        self.direction = direction
        self.rect = self.image_file.get_rect()

    def turn(self, direction, playerImages):
        keys = pygame.key.get_pressed()
        if keys[pygame.K_a] == True:
            self.direction -= 1
            if self.direction < -3:
                self.direction = 3
        if keys[pygame.K_d] == True:
            self.direction = 1
            if self.direction > 3:
                self.direction = 3

        if self.direction == -3:
            self.image_file = playerImages[0]
        if self.direction == -2:
            self.image_file = playerImages[1]
        if self.direction == -1:
            self.image_file = playerImages[2]
        if self.direction == 0:
            self.image_file = playerImages[3]
        if self.direction == 1:
            self.image_file = playerImages[4]
        if self.direction == 2:
            self.image_file = playerImages[5]
        if self.direction == 3:
            self.image_file = playerImages[6]

        return self.direction, self.image_file

I call it like:

skierDirection, playerImage = players.turn(skierDirection, playerImages)

The error I get is:

Traceback (most recent call last):
  File "C:\Users\Owen\Desktop\coding compile file\SkiFreeX\SkiFreeX.py", line 129, in <module>
    main()
  File "C:\Users\Owen\Desktop\coding compile file\SkiFreeX\SkiFreeX.py", line 122, in main
    skierDirection, playerImage = players.turn(skierDirection, playerImages)
TypeError: turn() missing 1 required positional argument: 'playerImages'
[Finished in 0.385s]

Any ideas?

回答1:

You are not supposed to call a class method directly, instead create an instance of that class:

p1 = players(your, values, here)
skierDirection, playerImage = p1.turn(skierDirection, playerImages)

To elaborate on the error you're getting:

TypeError: turn() missing 1 required positional argument: 'playerImages'

It's because turn needs an instance of players as first argument (self). A class method always gets passed the instance as the first argument, thus p1.turn(skierDirection, playerImages) will acutually pass 3 parameters to players.turn.

回答2:

You have need to use () with class name

Follow below code

skierDirection, playerImage = players().turn(skierDirection, playerImages)

来源：https://stackoverflow.com/questions/50594441/typeerror-missing-one-required-positional-argument

标签

python

object

typeerror