Python：在文件中搜索特定字符串并输出总字符串数

Question

Attempting to build a search functionality in python that takes an input value/string from the user, searches an external file, and then returns the total count (sum) of that requested value in the file.

if user_search_method == 1:
with open("file.txt", 'r') as searchfile:
    for word in searchfile:
        word = word.lower()
        total = 0
        if user_search_value in word.split():
            total += word.count(user_search_value)
            print total

When I run this though I get a line-by-line count displayed and not a total sum. When I add up those lines they are always 1 count short of the actual too.

Answer 1

You are printing the total in each iteration, you have to put it out of for loop. Also you can do this job more pythonic, using one generator expression:

if user_search_method == 1:
    with open("file.txt") as searchfile:
        total = sum(line.lower().split().count(user_search_value) for line in searchfile)
    print total

Answer 2

It feels like there might be something missing from your question, but I will try to get you to where it seems you want to go...

user_search_value = 'test'                     # adding this for completeness of 
                                               # this example
if user_search_method == 1:
    with open("file.txt", 'r') as searchfile:
        total = 0
        for word in searchfile:
            words = word.lower().split()       # breaking the words out, upfront, seems
                                               # more efficient

            if user_search_value in words:
                total += words.count(user_search_value)
        print total                            # the print total statement should be outside the for loop

Answer 3

if user_search_method == 1:    
  total = 0    
  with open('file.txt') as f:
    for line in f:
      total += line.casefold().split().count(user_search_value.casefold())
  print(total)

This is probably what you wanted doing.