Gets the n-th prime number. input: positive integer 'n' >= 0 returns the n-th prime number, beginning at index 0
(n)
| 416 | # ---------------------------------- |
| 417 | |
| 418 | def getPrime(n): |
| 419 | """ |
| 420 | Gets the n-th prime number. |
| 421 | input: positive integer 'n' >= 0 |
| 422 | returns the n-th prime number, beginning at index 0 |
| 423 | """ |
| 424 | |
| 425 | # precondition |
| 426 | assert isinstance(n,int) and (n >= 0), "'number' must been a positive int" |
| 427 | |
| 428 | index = 0 |
| 429 | ans = 2 # this variable holds the answer |
| 430 | |
| 431 | while index < n: |
| 432 | |
| 433 | index += 1 |
| 434 | |
| 435 | ans += 1 # counts to the next number |
| 436 | |
| 437 | # if ans not prime then |
| 438 | # runs to the next prime number. |
| 439 | while not isPrime(ans): |
| 440 | ans += 1 |
| 441 | |
| 442 | # precondition |
| 443 | assert isinstance(ans,int) and isPrime(ans), \ |
| 444 | "'ans' must been a prime number and from type int" |
| 445 | |
| 446 | return ans |
| 447 | |
| 448 | # --------------------------------------------------- |
| 449 |