【Python】reduce()
阿新 • • 發佈:2018-12-10
Describe
Answer
from functools import reduce CHAR_TO_FLOAT = { '0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9, '.': -1 } def str2float(s): nums = map(lambda ch: CHAR_TO_FLOAT[ch], s) point = 0 def to_float(f, n): nonlocal point if n == -1: point = 1 return f if point == 0: return f * 10 + n else: point = point * 10 return f + n / point return reduce(to_float, nums, 0.0) print(str2float('0')) print(str2float('123.456')) print(str2float('123.45600')) print(str2float('0.1234')) print(str2float('.1234')) print(str2float('120.0034'))
Output
0.0
123.456
123.456
0.12340000000000001
0.12340000000000001
120.0034