在python中,什么是逐行读取标准In的功能性、内存效率高的方法?

只是重复一下 sys.stdin ,它将在行上迭代。

map filter 如果你愿意的话。进入的每一行都将通过管道,在此过程中不会生成任何列表。

以下是每种方法的示例:

import sys

stripped_lines = (line.strip() for line in sys.stdin)
lines_with_prompt = ('--> ' + line for line in stripped_lines)
uppercase_lines = map(lambda line: line.upper(), lines_with_prompt)
lines_without_dots = filter(lambda line: '.' not in line, uppercase_lines)

for line in lines_without_dots:
    print(line)

在行动中,在终端中:

thierry@amd:~$ ./test.py 
My first line
--> MY FIRST LINE 
goes through the pipeline
--> GOES THROUGH THE PIPELINE
but not this one, filtered because of the dot. 
This last one will go through
--> THIS LAST ONE WILL GO THROUGH

只是,在哪里 地图 stdin :

import sys

uppercase_lines = map(lambda line: line.upper(), sys.stdin)

for line in uppercase_lines:
    print(line)

在行动中:

thierry@amd:~$ ./test2.py 
this line will turn
THIS LINE WILL TURN

to uppercase
TO UPPERCASE