from functools import reduce
def str2int(s):
def fn(x, y):
return x * 10 + y
def char2num(s):
return {'0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9}[s]
return reduce(fn, map(char2num, s))
我正在學習函數map()和reduce()。 {...} [。]是什麼意思?{..} [..]是什麼意思?