Counting Substrings from a List, inside a String

I want to have a list of substrings look for inside of a string, and to receive the count of however many times a substring appears in that string.

list = ['one', 'two', 'three']
str = "one one two four five six"
count = str.count(list)

So in this example, count should be 3. However, .count() can't read strings from a list for some reason, so I'm not sure how to work around that.

One way is to use sum with a generator expression and utilizing set for O(1) lookup. str.split() splits your string into a list, separating by whitespace.

str_set = {'one', 'two', 'three'}
x = 'one one two four five six'

count = sum(i in str_set for i in x.split())

print(count)  # 3

The reason this works is bool is a subclass of int, so we can sum True elements as if they are integers.

Note you have a list and string, no tuple involved. In addition, do not name variables after classes (e.g. list, str, set).