Python/project_euler/problem_07/sol2.py
Dhruv 719c5562d9
Add default args and type hints for problem 7 (#2973)
- Add default argument values
- Add type hints
- Change one letter variable names to a more descriptive one
- Add doctest for `solution()`
2020-10-08 07:57:47 +02:00

77 lines
1.8 KiB
Python

"""
Problem 7: https://projecteuler.net/problem=7
By listing the first six prime numbers:
2, 3, 5, 7, 11, and 13
We can see that the 6th prime is 13. What is the Nth prime number?
"""
def isprime(number: int) -> bool:
"""Determines whether the given number is prime or not"""
for i in range(2, int(number ** 0.5) + 1):
if number % i == 0:
return False
return True
def solution(nth: int = 10001) -> int:
"""Returns the n-th prime number.
>>> solution(6)
13
>>> solution(1)
2
>>> solution(3)
5
>>> solution(20)
71
>>> solution(50)
229
>>> solution(100)
541
>>> solution()
104743
>>> solution(3.4)
5
>>> solution(0)
Traceback (most recent call last):
...
ValueError: Parameter nth must be greater or equal to one.
>>> solution(-17)
Traceback (most recent call last):
...
ValueError: Parameter nth must be greater or equal to one.
>>> solution([])
Traceback (most recent call last):
...
TypeError: Parameter nth must be int or passive of cast to int.
>>> solution("asd")
Traceback (most recent call last):
...
TypeError: Parameter nth must be int or passive of cast to int.
"""
try:
nth = int(nth)
except (TypeError, ValueError):
raise TypeError(
"Parameter nth must be int or passive of cast to int."
) from None
if nth <= 0:
raise ValueError("Parameter nth must be greater or equal to one.")
primes = []
num = 2
while len(primes) < nth:
if isprime(num):
primes.append(num)
num += 1
else:
num += 1
return primes[len(primes) - 1]
if __name__ == "__main__":
print(solution(int(input().strip())))