如果你面对一个非常大/巨大的文件，并且想读得更快（假设你在TopCoder或HackerBank编码竞赛中），你可以一次将相当大的行块读入内存缓冲区，而不只是在文件级别逐行迭代。

buffersize = 2**16
with open(path) as f:
    while True:
        lines_buffer = f.readlines(buffersize)
        if not lines_buffer:
            break
        for line in lines_buffer:
            process(line)

根据Python的文件对象方法，将文本文件转换为列表的最简单方法是：

with open('file.txt') as f:
    my_list = list(f)
    # my_list = [x.rstrip() for x in f] # remove line breaks

演示

如果只需要遍历文本文件行，可以使用：

with open('file.txt') as f:
    for line in f:
       ...

旧答案：

使用with和readline（）：

with open('file.txt') as f:
    lines = f.readlines()

如果您不关心关闭文件，这一行程序将起作用：

lines = open('file.txt').readlines()

传统方式：

f = open('file.txt') # Open file on read mode
lines = f.read().splitlines() # List with stripped line-breaks
f.close() # Close file

这比必要的更明确，但可以做到你想要的。

with open("file.txt") as file_in:
    lines = []
    for line in file_in:
        lines.append(line)

这段代码将把整个文件读入内存，并删除每行末尾的所有空白字符（换行符和空格）：

with open(filename) as file:
    lines = [line.rstrip() for line in file]

如果您正在处理一个大文件，那么您应该逐行读取并处理它：

with open(filename) as file:
    for line in file:
        print(line.rstrip())

在Python 3.8及以上版本中，可以使用while循环和walrus运算符，如下所示：

with open(filename) as file:
    while (line := file.readline().rstrip()):
        print(line)

根据您计划对文件执行的操作以及文件的编码方式，您可能还需要手动设置访问模式和字符编码：

with open(filename, 'r', encoding='UTF-8') as file:
    while (line := file.readline().rstrip()):
        print(line)

具有文本文件内容：

line 1
line 2
line 3

我们可以在上面txt的同一目录中使用此Python脚本

>>> with open("myfile.txt", encoding="utf-8") as file:
...     x = [l.rstrip("\n") for l in file]
>>> x
['line 1','line 2','line 3']

使用追加：

x = []
with open("myfile.txt") as file:
    for l in file:
        x.append(l.strip())

Or:

>>> x = open("myfile.txt").read().splitlines()
>>> x
['line 1', 'line 2', 'line 3']

Or:

>>> x = open("myfile.txt").readlines()
>>> x
['linea 1\n', 'line 2\n', 'line 3\n']

Or:

def print_output(lines_in_textfile):
    print("lines_in_textfile =", lines_in_textfile)

y = [x.rstrip() for x in open("001.txt")]
print_output(y)

with open('001.txt', 'r', encoding='utf-8') as file:
    file = file.read().splitlines()
    print_output(file)

with open('001.txt', 'r', encoding='utf-8') as file:
    file = [x.rstrip("\n") for x in file]
    print_output(file)

输出：

lines_in_textfile = ['line 1', 'line 2', 'line 3']
lines_in_textfile = ['line 1', 'line 2', 'line 3']
lines_in_textfile = ['line 1', 'line 2', 'line 3']

命令行版本

#!/bin/python3
import os
import sys
abspath = os.path.abspath(__file__)
dname = os.path.dirname(abspath)
filename = dname + sys.argv[1]
arr = open(filename).read().split("\n") 
print(arr)

运行方式：

python3 somefile.py input_file_name.txt