Python 2.7: find item in list ignoring case

Question

I have a list of strings

["oranges", "POTATOES", "Pencils", "PAper"]

I want to find whether the list contains paper, ignoring case; so that the following code snippet should print found. My list only contains simple strings constituted of only the English alphabet -- upper and lower cases.

item = 'paper'
stuff = ["oranges", "POTATOES", "Pencils", "PAper"]
if item in stuff:
    print "found"
else:
   print "Not found"

#How do I get the method to print "found"?

CLARIFICATION:

My list is actually a list of lists and my logic is using the following construct:

if not any ( item in x for x in stuff):
   print "Not found"
else:
   print "found"

Solution 1

I'd combine lower with any:

>>> stuff = ["oranges", "POTATOES", "Pencils", "PAper"]
>>> any(s.lower() == 'paper' for s in stuff)
True
>>> any(s.lower() == 'paperclip' for s in stuff)
False

This will short-circuit and stop searching as soon as it finds one (unlike a listcomp). OTOH, if you're going to be doing multiple searches, then you might as well use a listcomp to lower the whole list once.

For your updated case (why is it that no one ever asks the question they're interested in, but a different question instead?), I'd probably do something like

>>> any("book" in (s.lower() for s in x) for x in stuff)
True
>>> any("paper" in (s.lower() for s in x) for x in stuff)
True
>>> any("stuff" in (s.lower() for s in x) for x in stuff)
False

The same rule holds, though. If you're doing multiple searches, you're probably better off canonicalizing the list-of-lists once.

Solution 2

You can use List Comprehension to convert the list to lowercase.

if item in [x.lower() for x in stuff]:
    print "found"
else:
    print "not found"

stuff = ["oranges", "POTATOES", "Pencils", "PAper"]
print [x.lower() for x in stuff]
['oranges', 'potatoes', 'pencils', 'paper']

Solution 3

Convert both strings to either upper case or lower case and compare them?

item = 'paper'
stuff = ["oranges", "POTATOES", "Pencils", "PAper"]
if item.upper() in map(lambda x: x.upper(), stuff):
    print "found"
else:
    print "Not found"

Extra: Then use this line

if not any ( item.upper() in map(lambda y: y.upper(), x) for x in stuff):

Solution 4

not a python buff and in general new to programming, but well, here is my solution:

I tried to stay close to your general approach, however you might want to look into encapsulating the code within a function.

I don't know about your level of experience, so please pardon if I'm posting something that you already are familiar with

Here some general information on functions: wikipedia

Here Pythons documentation on functions: Python Documentation

First solution, verbose but more understandable for someone new to this:

def item_finder_a(item, stuff):
    new_array = []
    for w in stuff:
        new_array.append(w.lower())
    if item in new_array:
        print "found"
    else:
       print "Not found"

item_finder(word,array_of_words)

And the slightly shorter more concise version

def item_finder_b(item, stuff):
    if item in map(str.lower,stuff):
        print "found"
    else:
       print "Not found"

item_finder_b(word,array_of_words)

Hope this helps

Cheers

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Comments

[kasavbere]

Thanks you so much for the elegant response!