从列表中找到单词的 position

Question

Hi I'm doing an assignment for school and part of it involves displaying the position of a word in a sentence and I searched it up and found this:

for i in [i for i,x in enumerate(list, start=1) if x == word]:
     print (i)

However I don't understand how this works so could someone please break it up and explain it to me

If it helps this is the rest of my code for this part of the assignment:

list = ["apple", "banana", "carrot","pear"]
print (list)
word = input("Enter a word from this list: ")
for i in [i for i,x in enumerate(list, start=1) if x == word]:
      print (i)

Answer 1

Awkwardness

First, you should not use list as a variable because list is one of the default Python functions. If you do so, the list() function (which is also a type) is replace by your variable in the local scope. So I renamed it alist .

alist = ["apple", "banana", "carrot", "pear"]

Explanation

The following statement is a comprehension list:

result = [i for i, x in enumerate(alist, start=1) if x == word]

This comprehension list can be written like this:

result = []
for i, x in enumerate(alist, start=1):
    if x == word:
        result.append(i)

For instance:

>>> alist = ["apple", "banana", "carrot", "pear"]
>>> word = "carrot"
>>> [i for i, x in enumerate(alist, start=1) if x == word]
[3]

This comprehension list returns all the positions of the word "carrot" in ["apple", "banana", "carrot", "pear"].

The loop:

for i in [i for i, x in enumerate(alist, start=1) if x == word]:
    print(i)

Is vainly complex because it iterates the comprehension list.

You can simplify like this:

print([i for i, x in enumerate(alist, start=1) if x == word])

Or:

for i, x in enumerate(alist, start=1):
    if x == word:
        print(i)

Note: alist.index(word) + 1 can give the first word position in the list.