I have a python list variable that contains strings. Is there a python function that can convert all the strings in one pass to lowercase and vice versa, uppercase?
解决方案
It can be done with list comprehensions. These basically take the form of [function-of-item for item in some-list]. For example, to create a new list where all the items are lower-cased (or upper-cased in the second snippet), you would use:
>>> [x.lower() for x in ["A","B","C"]]
['a', 'b', 'c']
>>> [x.upper() for x in ["a","b","c"]]
['A', 'B', 'C']
You can also use the map function:
>>> map(lambda x:x.lower(),["A","B","C"])
['a', 'b', 'c']
>>> map(lambda x:x.upper(),["a","b","c"])
['A', 'B', 'C']