| def find_nth(haystack, needle, n): | |
| """ | |
| Returns the starting index of the nth occurrence of the substring 'needle' in the string 'haystack'. | |
| """ | |
| start = haystack.find(needle) | |
| while start >= 0 and n > 1: | |
| start = haystack.find(needle, start + len(needle)) | |
| n -= 1 | |
| return start | |
| def round_base(num, base=10): | |
| """ | |
| Rounding a number to its nearest multiple of the base. round_base(49.2, base=50) = 50. | |
| """ | |
| return base * round(num / base) |