在一个句子中而不是一个单词中找到一个单词（python）

Question

In Python im trying to find a word in a sentece by using:

if word in sentence:
    number = number + 1

This works fine for finding a word in a sentence, the problem im running into is that this code finds the word inside other words. For example:

word = "or"
sentence = "Python or Java use a lot of words"
if word in sentence:
    number = number + 1

number will equal 2 instead of 1 because "or" is after "Python" and before "Java", and it also finds "or" in the word "word" Im trying to find a way to find just the word "or" by itself, instead of the program finding it in the sentence and in another word.

Answer 1

"Python or Java use a lot of words".lower().split().count('or')

should do it.

lower converts all of the text to lower case, split turns it into a list (space is the default delimiter) then count does a count against the list.

Answer 2

You need to split the sentence first using str.split :

>>> sentence = "Python or Java use a lot of words"
>>> sentence.split()
['Python', 'or', 'Java', 'use', 'a', 'lot', 'of', 'words']
>>>

This will give you a list of the words. After that, your code will work:

>>> # I made this so I didn't get a NameError
>>> number = 0
>>> word = "or"
>>> sentence = "Python or Java use a lot of words"
>>> if word in sentence.split():
...     # This is the same as "number = number + 1"
...     number += 1
...
>>> number
1
>>>

Answer 3

You can try splitting the sentence first, as so

if word in sentence.split(" "):

This will split sentence into an array of words, assuming all the words are separated by a single space. This is equivalent to using

if word in [ "Python", "or", "Java", "use", "a", "lot", "of", "words" ]:

which will check if the whole word exists in the list, rather than checking for substrings in the original sentence