step 1: 得到列表化的数字串

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] L = list(map(char2num,'12345.6'))

step 2: 分离小数点前后的数字为L1和L2，其中L2采用倒序

L1 = [] n = 0 while n < len(L): if L[n] != ".": L1.append(L[n]) else: break n = n + 1

step 2.1: 如果n=len(L)，说明一直没发现小数点，说明是整数，L2直接为空

L2 = [] if n == len(L): L2 = [] else: m = n + 1 while m < len(L): L2.append(L[m]) m = m + 1 L2rev = L2[-1::-1]

step 3: 这次是来真的了！那个……题目是什么来着？

from functools import reduce

def L1tofloat(a): def fn(x1, y1): return x1 * 10 + y1 def char1tonum(a): return {'0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9}[a] return reduce(fn, map(char1tonum, a))

def L2tofloat(b): def fm(x2, y2): return x2 / 10 + y2 def char2tonum(b): return {'0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, '9': 9}[b] return reduce(fm, map(char2tonum, b))/10

step 3.1: 同2.1的处理

if n == len(L): resultL = (L1tofloat(L1)) else: resultL = (L1tofloat(L1) + L2tofloat(L2rev))

print (resultL)

step 3.2: 增加验证是否为浮点数

print ('isinstance = float:', isinstance(resultL, float))