I want to check if a variable has one of multiple values. I'm confused about why or
doesn't work in this situation. I was following a tutorial that gave the example if (a or b):
, but when I try to do this it only checks the variable against the first value. What is wrong with my check?
name = raw_input('Please type in your name:')
if len(name) < 5:
print "Your name has fewer than 5 characters"
elif len(name) == 5:
print "Your name has exactly 5 characters"
if name == ("Jesse" or "jesse"):
print "Hey Jesse!"
else:
print "Your name has greater than 5 characters"
Answer
("Jesse" or "jesse")
The above expression tests whether or not "Jesse"
evaluates to True
. If it does, then the expression will return it; otherwise, it will return "jesse"
. The expression is equivalent to writing:
"Jesse" if "Jesse" else "jesse"
Because "Jesse"
is a non-empty string though, it will always evaluate to True
and thus be returned:
>>> bool("Jesse") # Non-empty strings evaluate to True in Python
True
>>> bool("") # Empty strings evaluate to False
False
>>>
>>> ("Jesse" or "jesse")
'Jesse'
>>> ("" or "jesse")
'jesse'
>>>
This means that the expression:
name == ("Jesse" or "jesse")
is basically equivalent to writing this:
name == "Jesse"
In order to fix your problem, you can use the in
operator:
# Test whether the value of name can be found in the tuple ("Jesse", "jesse")
if name in ("Jesse", "jesse"):
Or, you can lowercase the value of name
with str.lower
and then compare it to "jesse"
directly:
# This will also handle inputs such as "JeSSe", "jESSE", "JESSE", etc.
if name.lower() == "jesse":
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