Python暂时将字母改为小写

Question

I have a list that looks like this:

separate=[['I','wnet','to','the','mal,'],['and','bouht','a','new','shirt.'],['What','did','you','do','todya?']]

I'm going to run this through a program which will identify the misspelled words and replace them with the correct word but the list of words in the Webster Dictionary that I am using only uses lowercase letters. Can I temporarily change all of the letters to lowercase but then in the end return the original upper and lower case words?

I know about str.upper() and str.lower() and set.capitalize .

It seems like I want to use something like str.capwords() but inversely... I want to split the list into words(already done) and then make capital letters lower case.

Answer 1

Just use str.lower . It will return a new string with lower letter and keep the original string unchanged. So when you loop through the list such as if string.lower() in adict: , you do use the lower case to compare and the original string unchanged.

>>> a = 'ABC'
>>> a.lower()
'abc'
>>> a
'ABC'