Python Certificate - probability Calculator wrong Test values

Python
1

Hello Everyone,
i am currently working on the probability Calculator for the Scientific Programming python Certificate. And i cant get the last test (“test_prob_experiment”) running, as i dont cant get the correct Value for the expected probability. Can it be the case that the wished value is not correct set ? Because every solution i’ve compared ran into the same problem
image

2

No, the target value is correct. If you post your code, we can help you find the problem in your code.

3

I would like to but i’m not sure wether i would violate the rules for the forum as this is a Certificate Task. But i guess if the value is correct I need to find the error. Thank you for your fast reply!

4

You can post your code and ask questions on the forum - that’s what the forum is for.

5

Okay there you go :smiley:

import copy
import random

# Consider using the modules imported above.



class Hat:
 
  def __init__(self, **kwargs):
    self.contents = []
    for name, number in kwargs.items():
      for j in range(0, int(number)):
        self.contents.append(name)

  def draw(self, number_of_drawables):
    draws = []
    if number_of_drawables > len(self.contents):
      return self.contents
    
    for ball in range(0, number_of_drawables):
      ball = random.choice(self.contents)
      draws.append(ball)
      self.contents.remove(ball)
    return draws
    
def experiment(hat, expected_balls, num_balls_drawn, num_experiments):

  def check_expectations(actuals, expected):
    
    draws = {}
    for i in actuals:
      if i in draws:
        draws[i] = draws[i] + 1
      else:
        draws[i] = 1
    actuals = draws

    for color,count in expected.items():
      if color not in actuals:
        return False
      elif count>actuals[color]:
        return False
      else:
        return True

  def format_readable(actuals):
    draws = {}
    for i in actuals:
      if i in draws:
        draws[i] = draws[i] + 1
      else:
        draws[i] = 1
    actuals = draws
    return actuals

  
  success = 0
  for i in range(0, num_experiments):
    
    try:
      copied_hat = copy.deepcopy(hat)
    except copy.Error as e:
      print(f'An error Occured while copying object {e}')
   
    
    actuals = copied_hat.draw(number_of_drawables=num_balls_drawn)
    if check_expectations(actuals, expected_balls):
      success = success + 1

    return success / num_experiments
6

Why this condition?

7

to prevent a wrong value if there are not enough balls in the correct color. E.g if you are expecting two yellow balls, but only one is drawn

8

You are always returning false with that condition somehow, so its not doing what you think

9

What do you mean exactly ?

10

AssertionError: 0.0 != 0.272 within 0.01 delta (0.272 difference) : Expected experiment method to return a different probability.

Did you see this error?

I found one bug that is contributing to this -

This line is indented wrong

11

When I replace this with my code for the same, it works, so the error is in this function here.

12

Oh yeah this was an indention error. I must have made a mistake while copying. I get 0.293 as resulting probability. But let me double check the function

13

Ahha, error is here

1 Like
14

I think i still dont understand the error. Can you maybe explain ? Im feeling kinda lost :smiley:

15

Gosh found it. The else was unnecessary and wrong! Now it works like a charme! Thank you for your support!

1 Like
16

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