获取文件 Python 中某个短语的行号

Get Line Number of certain phrase in file Python

提问by Zac Brown

I need to get the line number of a phrase in a text file. The phrase could be:

我需要获取文本文件中短语的行号。这句话可以是：

the dog barked

I need to open the file, search it for that phrase and print the line number.

我需要打开文件，搜索该短语并打印行号。

I'm using Python 2.6 on Windows XP

我在 Windows XP 上使用 Python 2.6

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This Is What I Have:

这就是我所拥有的：

o = open("C:/file.txt")
j = o.read()
if "the dog barked" in j:
     print "Found It"
else:
     print "Couldn't Find It"

This is not homework, it is part of a project I am working on. I don't even have a clue how to get the line number.

这不是家庭作业，它是我正在进行的项目的一部分。我什至不知道如何获得行号。

采纳答案by Sacha

lookup = 'the dog barked'

with open(filename) as myFile:
    for num, line in enumerate(myFile, 1):
        if lookup in line:
            print 'found at line:', num

回答by slezica

Open your file, and then do something like...

打开您的文件，然后执行类似...

for line in f:
    nlines += 1
    if (line.find(phrase) >= 0):
        print "Its here.", nlines

There are numerous ways of reading lines from files in Python, but the for line in ftechnique is more efficient than most.

在 Python 中有多种从文件中读取行的for line in f方法，但该技术比大多数方法更有效。

回答by dr jimbob

f = open('some_file.txt','r')
line_num = 0
search_phrase = "the dog barked"
for line in f.readlines():
    line_num += 1
    if line.find(search_phrase) >= 0:
        print line_num

EDIT 1.5 years later (after seeing it get another upvote): I'm leaving this as is; but if I was writing today would write something closer to Ash/suzanshakya's solution:

1.5 年后编辑（在看到它再次获得投票后）：我将保持原样；但如果我今天写的话会写一些更接近 Ash/suzanshakya 的解决方案：

def line_num_for_phrase_in_file(phrase='the dog barked', filename='file.txt')
    with open(filename,'r') as f:
        for (i, line) in enumerate(f):
            if phrase in line:
                return i
    return -1

• Using withto open files is the pythonic idiom -- it ensures the file will be properly closed when the block using the file ends.
• Iterating through a file using for line in fis much better than for line in f.readlines(). The former is pythonic (e.g., would work if fis any generic iterable; not necessarily a file object that implements readlines), and more efficient f.readlines()creates an list with the entire file in memory and then iterates through it. * if search_phrase in lineis more pythonic than if line.find(search_phrase) >= 0, as it doesn't require lineto implement find, reads more easily to see what's intended, and isn't easily screwed up (e.g., if line.find(search_phrase)and if line.find(search_phrase) > 0both will not work for all cases as find returns the index of the first match or -1).
• Its simpler/cleaner to wrap an iterated item in enumeratelike for i, line in enumerate(f)than to initialize line_num = 0before the loop and then manually increment in the loop. (Though arguably, this is more difficult to read for people unfamiliar with enumerate.)

• 使用with打开文件是pythonic的习惯用法——它确保在使用文件的块结束时文件将被正确关闭。
• 遍历文件使用for line in f比for line in f.readlines(). 前者是pythonic（例如，如果f是任何通用的可迭代的，就可以工作；不一定是实现 的文件对象readlines），并且更有效地f.readlines()创建一个包含内存中整个文件的列表，然后遍历它。*if search_phrase in line比更Python if line.find(search_phrase) >= 0，因为它并不需要line实现find，读取更容易，看看有什么打算，并且不容易搞砸了（例如，if line.find(search_phrase)和if line.find(search_phrase) > 0都为所有案件的发现回报将无法正常工作的第一场比赛的索引或-1）。
• 它的简单/清洁剂在包装一个迭代的项目enumerate一样for i, line in enumerate(f)，而不是初始化line_num = 0循环之前，然后在循环手动递增。（虽然可以说，这对于不熟悉enumerate.的人来说更难阅读。）

See code like pythonista

查看类似 pythonista 的代码

回答by suzanshakya

def get_line_number(phrase, file_name):
    with open(file_name) as f:
        for i, line in enumerate(f, 1):
            if phrase in line:
                return i

回答by ghostdog74

for n,line in enumerate(open("file")):
    if "pattern" in line: print n+1

回答by M. kavin babu

listStr = open("file_name","mode")

if "search element" in listStr:
    print listStr.index("search element")  # This will gives you the line number

回答by Onkar Raut

Here's what I've found to work:

这是我发现的工作：

f_rd = open(path, 'r')
file_lines = f_rd.readlines()
f_rd.close()

matches = [line for line in file_lines if "chars of Interest" in line]
index = file_lines.index(matches[0])

回答by Amarjeet Ranasingh

suzanshakya, I'm actually modifying your code, I think this will simplify the code, but make sure before running the code the file must be in the same directory of the console otherwise you'll get error.

suzanshakya，我实际上是在修改你的代码，我认为这会简化代码，但在运行代码之前确保文件必须在控制台的同一目录中，否则你会得到错误。

lookup="The_String_You're_Searching"
file_name = open("file.txt")
for num, line in enumerate(file_name,1):
        if lookup in line:
            print(num)