Simple Python Function

Question

I did simple python function which takes two inputs and output some text.

Here it is,

def weather():
 israining_str=input("Is it raining (1 or 0) ? ")
 israining = bool(israining_str)
 temp_str=input("What is the temp ? ")
 temp = float(temp_str)
 if israining==True and temp<18:
 return "Umbrella & Sweater"
 elif israining==True and temp>=18:
 return "Umbrella"
 elif israining==False and temp<18:
 return "Sweater"
 else:
 return "Cap"

Test data -

>>> 
Is it raining ? 0
What is the temp ? 43
Umbrella
>>> ================================ RESTART ================================
>>> 
Is it raining ? 1
What is the temp ? 43
Umbrella
>>> 

If raining is false it shroud give Sweater or Cap. But my code gives true even israining_str == 0 or israining_str == 1

Where am i doing wrong ?

• Joe M.: Comment, testing directly for bool values by comparing with True or False is not a very good style, since you can write "if israining:". with the equivalent meaning to "if bool(israining) == True:" - but being shorter and clearer. (likewise you should write "if not israining:" in the third branch)

Answer 1

Here is your problem:

>>> bool("0")
True

Any nonempty string is True when converted to a boolean. You could do bool(int(israining_str)) to convert to int and then bool, which will give you the number zero if the person inputs the string "0".

Answer 2

Are you using python 3.x? If so, input returns a string. bool(youstring) will return True if the string is non-empty.

Answer 3

According to python's documentation:

bool(x)

Convert a value to a Boolean, using the standard truth testing procedure. If x is false or omitted, this returns False.

You pass non-empty string to this function, non-empty string is True.

You can write something like that:

t = int(israining_str)
# here you can check if user's input is 0 or 1 and ask user again if it is not
israining = False
if t:
 israining = True