Python if expression does not work correctly with raw input

Question

This script does not progress passed the first if expression! If the user enters DD, or F, the script acts as like the if state was true.

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)

score 2 · Accepted Answer · answered Nov 08 '14 at 03:32

2

Your if statements will always evaluate to True currently.

if choice == "D" or "d" evaluates to True on either the value of choice equaling "D", or the value of literal "d" being True; and the second part is thus always True.

Instead, use

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

answered Nov 08 '14 at 03:32

Anshul Goyal

73,278
37
149
186

choice.lower() or choice.upper() then test only once. – Rafael Barros Nov 08 '14 at 03:35
@RafaelBarros I don't think that will provide much advantage, calling a function will always be more costlier that using literals – Anshul Goyal Nov 08 '14 at 03:37
I see your point, and I agree. Also: more costly. – Rafael Barros Nov 08 '14 at 03:41
thanks, i've been stuck all day on this. – mdandr Nov 08 '14 at 03:42

Python if expression does not work correctly with raw input

1 Answers1