20 lines
432 B
Python
20 lines
432 B
Python
# Lesson 2 Task 4: get number factorial
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# Author: Stanislav Mykhailenko
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# License: Unlicense
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error = False
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try: number = int(input("Enter a natural number: "))
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except ValueError: error = True
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if not error and number < 1: error = True
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if not error:
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factorial = 1
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for i in range(2, number + 1):
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factorial = factorial * i
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else:
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print(str(number) + " factorial is " + str(factorial))
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else:
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print("Invalid number entered.")
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