如何得到多个“密钥”对于一个命令

Question

如何设置多个输入一个命令：

while True: 
    option = input('What Units Are You Using? (Q to Quit) ').lower() 
    if option == ['millimeters' , 'mm']: 
     a = int(input('Enter Your number: ')) 
     while True: 
      b = a/10 # centimeters 
      c = a/1000 # meters 
      print('Okay- Heres what we got:', b,'centimeters(cm) and', c,' meters (m)') 
      break 

所以对：如果选择== [“毫米”，“毫米”]：我如何让它运行毫米和毫米？ （Python的3.33） 感谢

Answer 1

您可以使用in运营商（其中检查成员是否存在），这样

if option in ['millimeters' , 'mm']: 

现在，if条件将得到满足，如果option或者是millimeters或mm。

建议：

1. 你并不需要在这里无限循环。
2. 您可以使用format方法组成字符串。

那么，你的改进方案看起来像这样

while True: 
    option = input('What Units Are You Using? (Q to Quit) ').lower() 
    if option in ['millimeters' , 'mm']: 
     a = int(input('Enter Your number: ')) 
     b, c = a/10, a/1000 
     print('Okay- Heres what we got: {} centimeters(cm) and {} meters (m)'.format(b, c)) 

Answer 2

while True: 
    option = input('What Units Are You Using? (Q to Quit) ').lower() 

    if option == 'millimeters' or option == 'mm': 

     a = int(input('Enter Your number: ')) 

     while True: 


      b = a/10 # centimeters 

      c = a/1000 # meters 

      print('Okay- Heres what we got:', b,'centimeters(cm) and', c,' meters (m)') 
      break 

Answer 3

下面是一个扩展版本：

import sys 

if sys.hexversion < 0x3000000: 
    inp = raw_input  # Python 2.x 
else: 
    inp = input   # Python 3.x 

class Unit: 
    def __init__(self, short_singular, short_plural, long_singular, long_plural, per_meter): 
     self.ss = short_singular 
     self.sp = short_plural 
     self.ls = long_singular 
     self.lp = long_plural 
     self.per_meter = per_meter 
     self.names = {short_singular, short_plural, long_singular, long_plural} 

    def match(self, name): 
     return name in self.names 

    def to_meters(self, amt): 
     return amt/self.per_meter 

    def from_meters(self, amt): 
     return amt * self.per_meter 

    def to_str(self, amt, sig=3, short=False): 
     if amt == 1.0: 
      s = self.ss if short else self.ls 
     else: 
      s = self.sp if short else self.lp 
     return "{{:0.{}f}} {{}}".format(sig).format(amt, s) 

units = [ 
    Unit('in', 'ins', 'inch',  'inches', 39.3701), 
    Unit('ft', 'ft', 'foot',  'feet',  3.28084), 
    Unit('yd', 'yds', 'yard',  'yards',  1.09361), 
    Unit('mi', 'mi', 'mile',  'miles', 0.000621371), 
    Unit('mm', 'mm', 'millimeter', 'millimeters', 1000.), 
    Unit('cm', 'cm', 'centimeter', 'centimeters', 100.), 
    Unit('m', 'm', 'meter',  'meters',   1.), 
    Unit('km', 'km', 'kilometer', 'kilometers', 0.001) 
] 

def get_unit(prompt): 
    while True: 
     name = inp(prompt).strip().lower() 
     for unit in units: 
      if unit.match(name): 
       return unit 
     print("I don't know that one.") 

def get_float(prompt): 
    while True: 
     try: 
      return float(inp(prompt)) 
     except ValueError: 
      pass 

def main(): 
    a = get_unit("Convert from what unit? ") 
    b = get_unit("To what unit? ") 
    amt = get_float("How many {}? ".format(a.lp)) 
    res = b.from_meters(a.to_meters(amt)) 
    print("The result is {}.".format(b.to_str(res))) 

if __name__=="__main__": 
    main() 

它运行像

Convert from what unit? km 
To what unit? in 
How many kilometers? 4.3 
The result is 169291.430 inches.