Let say, when student completed the course then he will get the percentage of his completion.
Then we implement the max ratings is 5 stars which following these rules:

• 0%-4% of percent score, will get 0 star
• 5%-19% of percent score, will get 1 star
• 20%-39% of percent score, will get 2 stars
• 40%-59% of percent score, will get 3 stars
• 60%-79% of percent score, will get 4 stars
• 80%-100% of percent score, will get 5 stars

So, based on student score:

• 0% of percent score will get 0 rating star.
• 19% of percent score will get 1 rating star.
• But, in another conditionals when student get 30% percent of score, then he should get 2.5 of rating stars based on above range rules.

NOTE: The max 5 stars is dynamic value, it can be 10 stars.

So far, here is the code to achieve above problem:

rate_settings = {
    "1": 10,
    "2": 20,
    "3": 30,
    "4": 60,
    "5": 80
}
required_rate = ["1", "2", "3", "4", "5"]


def calculate_rating(percent):
    rate_settings_keys = list(rate_settings.keys())
    rate_settings_values = list(rate_settings.values())
    if not all(map(lambda rate: rate in required_rate, rate_settings_keys)) or len(required_rate) != len(rate_settings_keys):
        raise Exception("invalid rate config")
    if any(map(lambda rate: rate < 0 or rate > 100, rate_settings_values)):
        raise Exception("invalid rate value, must be between 0 - 100")
    if rate_settings_values != sorted(rate_settings_values):
        raise Exception("invalid rate value, must be sorted")
    for rate in reversed(rate_settings):
        passing_value = rate_settings[rate]
        if percent >= passing_value:
            return rate
    return 0

print(calculate_rating(0))  # 0
print(calculate_rating(10))  # 1
print(calculate_rating(15))  # 1
print(calculate_rating(30))  # 3
print(calculate_rating(100))  # 5

As you can see, above script only achieve integer of stars, but yet for this issues:

• But, in another conditionals when student get 30% percent of score, then he should get 2.5 of rating stars based on above range rules.
• NOTE: The max 5 stars is dynamic value, it can be 10 stars.

how we can accomplish this?

Solved

Bassed on @Eilonlif answer, finally we solve this problem:

import statistics
from typing import Union

# Ratings with 5 stars
# 0%-4% => 0 star
# 5%-19% => 1 star
# 20%-39% => 2 stars
# 40%-59% => 3 stars
# 60%-79% => 4 stars
# 80%-100% => 5 stars

NUM_OF_RATINGS = 5
RANGE_SCORES = [
    (0, 4),
    (5, 19),
    (20, 39),
    (40, 59),
    (60, 79),
    (80, 100),
]


def percent_to_stars(percentage: Union[int, float, None], ranges=None):
    if not percentage:
        return None
    if ranges is None:
        ranges = RANGE_SCORES
    for index, range_score in enumerate(ranges):
        if range_score[0] <= percentage <= range_score[1]:
            middle = statistics.median(range(*range_score))
            if percentage >= middle:
                sum_rating = index   0.5
                if sum_rating < NUM_OF_RATINGS:
                    return sum_rating
            return index
    return -1


print(percent_to_stars(11))  # 1
print(percent_to_stars(99))  # 5
print(percent_to_stars(30))  # 2.5

CodePudding user response：

Here is the new code:

def percent_to_stars(percentage: int, ranges=None, decimal=False):
    if ranges is None:
        ranges = [(0, 4), (5, 20), (20, 40), (40, 60), (60, 80), (80, 101)]
    for i, r in enumerate(ranges):
        if r[0] <= percentage < r[1]:
            if decimal and percentage >= sum(r)//2:
                return min(i   0.5, len(ranges) - 1)
            return i
    return -1


print(percent_to_stars(30, decimal=True))
print(percent_to_stars(30))

The answer is edited to meet the requirements.

Personally, I feel your code is a bit hard to read, however, you don't have to use my implementation.

CodePudding user response：

Here is what I would do:

For perfect star calculations

while True:
    students_score = int(input("Enter the students score as a percentage: "))

    if students_score >= 0 and students_score <= 4:
        print("This student got 0 stars")
        print("")

    if students_score >= 5 and students_score <= 19:
        print("This student got 1 star")
        print("")

    if students_score >= 20 and students_score <= 39:
        print("This student got 2 stars")
        print("")

    if students_score >= 40 and students_score <= 59:
        print("This student got 3 stars")
        print("")
        
    if students_score >= 60 and students_score <= 79:
        print("This student got 4 stars")
        print("")

    if students_score >= 80 and students_score <= 100:
        print("This student got 5 stars")
        print("")

For decimal star calculations

while True:
    students_score = int(input("Enter the students score as a percentage: "))
    star_score = 5/100 * students_score
    print("This student got ",star_score," stars")
    print("")