Python在文本文件中搜索确切的单词/短语

时间:2014-12-03 22:56:23

标签: python

目前,我正在尝试在文本文件中搜索确切的字词/短语。我正在使用Python 3.4

这是我到目前为止的代码。

import re

def main():
    fileName = input("Please input the file name").lower()
    term = input("Please enter the search term").lower()

    fileName = fileName + ".txt"

    regex_search(fileName, term)

def regex_search(file,term):
    source = open(file, 'r')
    destination = open("new.txt", 'w')
    lines = []
    for line in source:
        if re.search(term, line):
            lines.append(line)

    for line in lines:
        destination.write(line)
    source.close()
    destination.close()
'''
def search(file, term): #This function doesn't work
    source = open(file, 'r')
    destination = open("new.txt", 'w')
    lines = [line for line in source if term in line.split()]

    for line in lines:
        destination.write(line)
    source.close()
    destination.close()'''
main()

在我的函数regex_search中,我使用正则表达式来搜索特定的字符串。但是,我不知道如何搜索特定的短语。

在第二个功能中,搜索,我将该行拆分为一个列表并在那里搜索该单词。但是,这将无法搜索特定的短语,因为我在['the','dog','walked']中搜索[“dog walked”],这将不会返回正确的行。

1 个答案:

答案 0 :(得分:2)

编辑:考虑到您不想匹配部分单词('foo'不匹配'foobar'),您需要向前看数据流。这个代码有点尴尬,所以我认为正则表达式(你当前的regex_search有一个修复)是要走的路:

def regex_search(filename, term):
    searcher = re.compile(term + r'([^\w-]|$)').search
    with open(file, 'r') as source, open("new.txt", 'w') as destination:
        for line in source:
            if searcher(line):
                destination.write(line)