将单词从文本文件添加到列表（python 2.7）

Question

Assuming I have a text file.
My goal is to write a function which receives a number of line to go over in the text file and returns a list, each cell in the list containing one word exactly from that line.
Any idea of how doing this ?

thanks

Answer 1

If you are working with small files:

def get_words(mifile, my_line_number):
    with open(mifile) as f:
        lines = f.readlines()
        myline = lines[my_line_number]    #first line is 0
        return myline.split()

you get all the file lines in the list lines . This is not very efficient for VERY big files. In that case probably it would be better to iterate line by line until you arrive to the chosen line.

Answer 2

Given the filename and the line number ( lineno ), you could extract the words on that line this way:

Assuming the lineno is not too large:

import linecache

line = linecache.getline(filename, lineno)
words = line.split()

Or, if the lineno is large:

import itertools

with open(filename,'r') as f:        
    line = next(itertools.islice(f,lineno-1,None))
    words = line.split()

This,of course,assumes that words are separated by spaces--which may not be the case in hard-to-parse text.