Python如果表达式在原始输入中无法正常工作

Question

此脚本不会传递第一个if表达式！ 如果用户输入DD或F，那么脚本就像if状态为真。

choice = raw_input("Cup size for bra: D, DD, or F: ") 
if choice == "D" or "d": 
    band_length = raw_input("Please enter the bra band length for your D size breasts: ") 
    D_Statistics(band_length) 
elif choice == "DD" or "dd": 
    band_length = raw_input("Please enter the bra band length for your DD size breasts: ") 
    DD_statistics(band_length) 
elif choice == "F" or "f": 
    band_length = raw_input("Please enter the bra band length for your F size breasts: ") 
    F_statistics(band_length) 

Answer 1

你if语句将始终评估为True目前。

if choice == "D" or "d"在等于“D”的choice的值或文字“d”的值为真的情况下计算为True;第二部分因此总是True。

相反，使用

if choice in ("D", "d"): 
    ... 
elif choice in ("DD", "dd"): 
    ... 
if choice in ("F", "f"): 
    ...