找到单词后如何遍历文件

Question

我正在文本文件中搜索输入词。但是，我只打算在“START”一词之后搜索文件中的文本。 “START”之前的前二十位应该被忽略。我知道如何找到“START”，但不知道如何在遇到“START”后搜索文件的其余部分。我会很感激任何指导！

这是我目前所拥有的：

file = open("EnglishWords.txt", "r")

print("***** Anagram Finder *****")
word = input("Enter a word: ")


for line in file:
    if "START" in line:
        if word in line:
            print("Yes, ", word, " is in the file.", sep="")
        else:
            print("Sorry, ", word, " is not in the file.", sep="")


file.close()

这是文本文件的示例：

    The name of Princeton University or Princeton may not be
     used in advertising or publicity pertaining to
     distribution of the software and/or database.  Title to
     copyright in this software, database and any associated
     documentation shall at all times remain with Princeton
     University and LICENSEE agrees to preserve same.
START
clobber
transversalis
squinter
cunner
damson
extrovertive
absorptive

Answer 1

修改您的代码，我们有

file = open("EnglishWords.txt", "r")

print("***** Anagram Finder *****")
word = input("Enter a word: ")


start_looking = False
word_found = False

for line in file:
    if not start_looking:
        if "START" in line:
            start_looking = True
        else:
            continue

    if word in line:
        print("Yes, ", word, " is in the file.", sep="")
        word_found = True
       break

if not word_found:
    print("Sorry, ", word, " is not in the file.", sep="")

file.close()

只要没有找到START，就一直跳过文件的行。但是，如果您遇到START，请重置您的标志并开始查找。

Answer 2

找到您的单词后发送for：

with open(myfile, 'r') as f:
    for line in f:
        if 'START' in line:
            # do stuff to lines below 'START'
            # you could do another for loop here to iterate
            for line in f:
                print (line) # just an example

与this 其他 SO 帖子非常相似。我的答案语法的功劳来自它的答案。

Answer 3

正则表达式模块怎么样？

re.findall(r"START.*(word_to_search).*", entire_text)

只有在要搜索的单词之前有一个 START 时，它才会返回结果。我希望这就是你要找的。​​p>

编辑： 对于逐行的解决方案，我会使用类似的东西：

start_search = 0
    with open(bigfile, "r") as f:
        for line in f:
            if "START" IN line:
                start_search = 1
            if start_search and word_to_search in line:
                print("result foun")
                return (word_to_search)

这个呢？

Answer 4

保持简短、简单和明确：

with open("EnglishWords.txt", 'r') as fin:
    output = fin.readlines()
    # Find the line that contains START
    index = output.index("START")
    # Search all the lines after that
    for line in output[index+1:]:
        if word in line:
            print("Yes, ", word, " is in the file.", sep="")
        else:
            print("Sorry, ", word, " is not in the file.", sep="")

Answer 5

您可以使用 Python 的 dropwhile() 来定位单词的开头并从那里迭代：

from itertools import dropwhile

print("***** Anagram Finder *****")
word = input("Enter a word: ").lower() + '\n'

with open("EnglishWords.txt") as f_words:
    if word in dropwhile(lambda r: not r.startswith("START"), f_words):
        print("Yes, {} is in the file".format(word.strip()))
    else:
        print("Sorry, {} is not in the file.".format(word.strip()))

Answer 6

您可以使用布尔值：

file = open(“testfile.txt”, “r”) 
foundStart = False
for line in file: 
    if foundStart:
         # do something...
    elif line == "START":
       foundStart = True