Question

所以我有两个python脚本，其中一个是在另一个中调用函数：

First（first.py）：

def get_values(number):

   ....

   for x in range(number):
        print x

秒（second.py）：

import first

....

data = first.get_values(10)

我的目标是将 get_value 的输出保存在 first.py 中，以保存为变量 data 作为列表（即[0 ，1,2,3，...]）。有没有办法做到这一点，而不在过程中打印这些值？

提前致谢！

编辑：我无法改变 first.py ，因为其他功能已经依赖于它的当前输出。

Answer 1

您可以使用redirect_stdout抓取标准输出：

#!/usr/bin/env python

import io
# if python3
# from contextlib import redirect_stdout
# if python2
import sys
from contextlib import contextmanager

# Note: I took this method from someone else's SO answer, but I think
#       they took it from someone else...etc.
@contextmanager
def redirect_stdout(new_target):
    old_target, sys.stdout = sys.stdout, new_target # replace sys.stdout
    try:
        yield new_target # run some code with the replaced stdout
    finally:
        sys.stdout = old_target # restore to the previous value

def get_values(number):
    values = tuple(range(number))
    for v in values:
        print(v)
    return values


def main():
    saved_stdout = io.StringIO()
    with redirect_stdout(saved_stdout):
        data = get_values(4)
    print(data)

    data = get_values(2)
    print(data)


main()

输出：

$ python stdout.py 
(0, 1, 2, 3)
0
1
(0, 1)

Answer 2

在first.py中创建一个如下列表：

def get_values(number):
    ....
    return [x for x in range(number)]

然后在second.py中你可以做到

data = first.get_values(10)

Answer 3

将输出重定向到io流，然后再读取（Python 3.5）。

import sys
import io
stdout = sys.stdout  # keep a handle on the real standard output
local_i = io.StringIO()
sys.stdout = local_i  # Choose a file-like object to write to
for i in range(10): # this is just an example, you have to call your function here from first.py
    print(i)
sys.stdout = stdout# revert to standard output

print("This printing is after the function call. You can process it as you want. This is just for demonstration purpose.")

for i in local_i.getvalue():
    if i != '\n':
        print(int(i))

对于Python 2：

import sys
import StringIO
stdout = sys.stdout  # keep a handle on the real standard output
local_i = StringIO.StringIO()
sys.stdout = local_i  # Choose a file-like object to write to
for i in range(10):
    print(i)
sys.stdout = stdout# revert to standard output

print(
    "This printing is after the function call. You can process it as you want. This is just for demonstration purpose")

for i in local_i.getvalue():
    if i != '\n':
        print(int(i))

输出：

This printing is after the function call. You can process it as you want. This is just for demonstration purpose.
0
1
2
3
4
5
6
7
8
9

将循环函数打印存储（重定向）到变量

3 个答案: