Error while trying to run a program in python

Question

I'm starting to study python, very early on. And, I tried to make a hello world, from the site of pycharm and, I came across this error,

C:\Users\henrique.carvalho\PycharmProjects\helloworld\venv\Scripts\python.exe C:/Users/henrique.carvalho/PycharmProjects/helloworld/venv/Car.py
Traceback (most recent call last):
  File "C:/Users/henrique.carvalho/PycharmProjects/helloworld/venv/Car.py", line 1, in <module>
    class Car():
  File "C:/Users/henrique.carvalho/PycharmProjects/helloworld/venv/Car.py", line 24, in Car
    my_car = Car()
NameError: name 'Car' is not defined

How to solve?

Follow the code:

class Car:
    def __init__(self):
        self.speed = 0
        self.odometer = 0
        self.time = 0

    def say_state(self):
        print("I'm going {} kph!".format(self.speed))

    def accelerate(self):
        self.speed += 5

    def brake(self):
       self.speed -= 5

    def step(self):
        self.odometer += self.speed
        self.time += 1

    def average_speed(self):
        return self.odometer / self.time

    if __name__ == '__main__':
        my_car = Car()
        print("I'm a car!")
        while True:
            action = input("What should I do?[A]ccelerate,[B]rake, show [O]dometer, or show average [S]peed?").upper()
            if action not in "ABOS" or len(action) != 1:
                print("I don't know thow to do that")
                continue
            if action == 'A':
                my_car.accelerate()
            elif action == 'B':
                my_car.brake()
            elif action == 'O':
                print("The car has driven {} kilometers".format(my_car.odometer))
            elif action == 'S':
                print("The car's average speed was {} kph".format(my_car.average_speed()))
            my_car.step()
            my_car.say_state()

I searched here on stackoverflow but I could not figure out the answer to my case.

indentation matters when writing code in python. It looks like you nested your main function under the class — usernamenotfound, Jun 26 '18 at 17:37
Un-indent what you intended as your main program. At the moment, it's part of the class "Car", which prevents you from creating an object with the usual syntax. — Prune, Jun 26 '18 at 17:38
`my_car = Car()` inside the definition of `Car` is incorrect. Why is this code inside the class definition? — lurker, Jun 26 '18 at 17:39

score 1 · Answer 1 · answered Jun 26 '18 at 17:38

1

In Python, the indentation matters while writing functions, loops, and classes. Be sure to move your main function outside of the class to make sure you get the desired output.

answered Jun 26 '18 at 17:38

pragmaticprog

550
2
15

thank you! better explanation than the downvoter – Jun 26 '18 at 17:40

score 0 · Answer 2 · answered Jun 26 '18 at 17:36

You have extra indentation from if __name__ == '__main__': line. Look at this updated code:

class Car:
    def __init__(self):
        self.speed = 0
        self.odometer = 0
        self.time = 0

    def say_state(self):
        print("I'm going {} kph!".format(self.speed))

    def accelerate(self):
        self.speed += 5

    def brake(self):
       self.speed -= 5

    def step(self):
        self.odometer += self.speed
        self.time += 1

    def average_speed(self):
        return self.odometer / self.time

if __name__ == '__main__':
    my_car = Car()
    print("I'm a car!")
    while True:
        action = input("What should I do?[A]ccelerate,[B]rake, show [O]dometer, or show average [S]peed?").upper()
        if action not in "ABOS" or len(action) != 1:
            print("I don't know thow to do that")
            continue
        if action == 'A':
            my_car.accelerate()
        elif action == 'B':
            my_car.brake()
        elif action == 'O':
            print("The car has driven {} kilometers".format(my_car.odometer))
        elif action == 'S':
            print("The car's average speed was {} kph".format(my_car.average_speed()))
        my_car.step()
        my_car.say_state()

Pankaj Singh · Accepted Answer · 2018-07-07T07:18:12.107

class Car:
  def __init__(self):
      self.speed = 0
      self.odometer = 0
      self.time = 0

  def say_state(self):
      print("I'm going {} kph!".format(self.speed))

  def accelerate(self):
      self.speed += 5

  def brake(self):
     self.speed -= 5

  def step(self):
      self.odometer += self.speed
      self.time += 1

  def average_speed(self):
      return self.odometer / self.time

if __name__ == '__main__':
  my_car = Car()
  print("I'm a car!")
  while True:
      action = input("What should I do?[A]ccelerate,[B]rake, show [O]dometer, or show average [S]peed?").upper()
      if action not in "ABOS" or len(action) != 1:
          print("I don't know thow to do that")
          continue
      if action == 'A':
          my_car.accelerate()
      elif action == 'B':
          my_car.brake()
      elif action == 'O':
         print("The car has driven {} kilometers".format(my_car.odometer))
      elif action == 'S':
          print("The car's average speed was {} kph".format(my_car.average_speed()))
      my_car.step()
      my_car.say_state()

Error while trying to run a program in python

3 Answers3