Question

How can I search list(s) where all the elements exactly match what I’m looking for. For instance, I want to verify if the following list consist of ‘a’, ‘b’ and ‘c’, and nothing more or less.

lst=['a', 'b', 'c']

I did this:

if 'a' in lst and 'b' in lst and 'c' in lst:
   #do something

Many thanks in advance.

Answer 1

You can sort the lists and then simply compare them: sorted( list_one ) == sorted( list_two ).

Also you can convert both lists to sets and compare them. But be careful, sets eat duplicate items! set( list_one ) == set( list_two ).

Sets can also tell you which items either set is lacking: set(list_one) ^ set(list_two).

Some examples:

>>> sorted("asd") == sorted("dsa")
True
>>> sorted( "asd" ) == sorted( "dsa" )
True
>>> sorted( "asd" ) == sorted( "dsaf" )
False
>>> set( "asd" ) == set( "dasf" )
False
>>> set( "asd" ) == set( "daas" )
True
>>> set( "asd" ) ^ set( "daf" )
set(['s', 'f'])