PTA 乙级 1024 科学计数法 (20分)

 1 num,inx = input().split("E")
 2 out = "" if num[0] == "+" else "-"    #输出的正负号
 3 a,de = num[1:].split(".")
 4 num0 = a+de
 5 num_ling = int(inx[1:])               # 指数大小
 6 q = len(de)                           # 小数部分位数
 7 if num_ling == 0:                     # 指数为零
 8     out += num[1:]
 9 elif inx[0] == "+":
10     w =  num_ling - q
11     if w < 0:                       
12         out += num0[:(num_ling+1)] + "." + num0[(num_ling+1):]
13     else:                             # 补零
14         out += num0 + "0" * w
15 else:
16     out = out + "0." + "0" * (num_ling-1) + num0 #指数小于零
17 print(out)