Python调用子进程subprocess

subprocess库用于在控制台中调用子进程，可以模拟控制台命令输入输出。

subprocess.run

如果只是简单调用运行第三方程序的话，使用subprocess.run最为简单。下面以调用ping命令为例

# 直接在控制台输出 但由于编码问题中文为乱码
subprocess.run(['ping', 'baidu.com'])
subprocess.run('ping baidu.com', shell=True)
# 通过stdout来获取输出
p = subprocess.run(['ping', 'baidu.com'], stdout=subprocess.PIPE)
print(p.stdout.decode('gbk'))

subprocess.Popen

下面以下面这个相加函数为例，利用subprocess.Popen来调用它

#!/usr/bin/env python
# -*- coding: utf-8 -*-
n = int(input())
nums = []
while n > 0:
    a, b = list(map(int, input().strip().split()))
    nums.append([a, b])
    n -= 1
for a, b in nums:
    print(f'{a}+{b}={a + b}')

仿照牛客网上测试程序的流程来进行输入输出，注意stdin的用法

def test(pyfile, datafile):
    p = subprocess.Popen(['python.exe', pyfile], stdin=subprocess.PIPE)
    with open(datafile) as f:
        line = f.readline()
        print('..........输入..........')
        while line:
            print(line.strip())
            p.stdin.write(line.encode())
            line = f.readline()

    p.stdin.close()
    print('..........输出..........')
    p.wait(2000)


test('add.py', 'data.txt')

# ..........输入..........
# 3
# 1 2
# 5 6
# 7 8
# ..........输出..........
# 1+2=3
# 5+6=11
# 7+8=15

如果有多个测试用例，可以在输入数据时用一个标志符#进行分割

def tests(pyfile, datafile):
    with open(datafile) as f:
        line = f.readline()
        n = 0
        while line.strip().startswith('#'):
            n += 1
            p = subprocess.Popen(['python.exe', pyfile], stdin=subprocess.PIPE)
            line = f.readline()
            print(f'..........案例[{n}]输入..........')
            while line:
                print(line.strip())
                p.stdin.write(line.encode())
                line = f.readline()
                if line.strip().startswith('#'):
                    break
            p.stdin.close()
            print(f'..........案例[{n}]输出..........')
            p.wait()


tests('add.py', 'data.txt')
# ..........案例[1]输入..........
# 3
# 1 2
# 5 6
# 7 8
# ..........案例[1]输出..........
# 1+2=3
# 5+6=11
# 7+8=15
# ..........案例[2]输入..........
# 2
# 1 2
# 5 6
# 7 8
# ..........案例[2]输出..........
# 1+2=3
# 5+6=11

参考

https://www.runoob.com/w3cnote/python3-subprocess.html https://docs.python.org/zh-cn/3/library/subprocess.html