subprocess.Popen
时间: 2023-07-26 17:06:08 浏览: 164
`subprocess.Popen` 是 Python 中用于创建新进程的模块。它提供了一种便捷的方式来启动一个新的进程,并与其进行交互。通过 `subprocess.Popen`,您可以在 Python 中启动另一个程序,然后与其进行通信。
在使用 `subprocess.Popen` 时,您需要指定要启动的程序及其参数。一旦启动,您可以使用 `communicate` 方法与子进程进行交互,或者使用 `stdin`、`stdout` 和 `stderr` 属性来分别访问子进程的输入、输出和错误流。
下面是一个简单的示例,演示如何使用 `subprocess.Popen` 启动并与另一个 Python 程序进行交互:
```python
import subprocess
# 启动另一个 Python 程序
p = subprocess.Popen(['python', 'other_program.py'], stdin=subprocess.PIPE, stdout=subprocess.PIPE)
# 向子进程发送数据并获取输出
output, _ = p.communicate(b'hello')
print(output.decode())
```
在这个例子中,我们使用 `subprocess.Popen` 启动了一个名为 `other_program.py` 的 Python 程序,并向其发送了字符串 `"hello"`。然后,我们使用 `communicate` 方法获取子进程的输出,并将其打印到控制台上。
相关问题
subprocess.popen
`subprocess.Popen` 是 Python 中一个用于创建新进程的函数。它允许你在 Python 脚本中启动一个新的进程,并与其进行交互。该函数接受一些参数,包括要执行的命令、命令行参数、执行环境、标准输入、标准输出和标准错误的处理方式等。
通常,使用 `Popen` 函数时需要指定 `stdout` 和 `stderr` 参数,以便在 Python 中获取被执行命令的输出信息。此外,还可以使用 `communicate()` 方法与所创建的子进程进行交互,向其发送数据并获取其返回的数据。
例如,以下代码可以在 Python 中启动一个新的进程,并在其中执行 `ls` 命令,然后获取其输出信息:
```
import subprocess
output = subprocess.Popen(['ls', '-l'], stdout=subprocess.PIPE).communicate()[0]
print(output)
```
这将在终端中输出 `ls -l` 命令的输出信息。
subprocess.Popen subprocess.run
subprocess.Popen and subprocess.run are both modules in Python's subprocess module that are used for running external commands. Here's a brief explanation of each:
1. subprocess.Popen: This function is used to create a new process and execute a command within it. It provides more flexibility and control over the execution process. Popen returns a Popen object, which allows you to interact with the running process, such as reading its output or terminating it.
Example usage:
```python
import subprocess
# Run a command and get its output
result = subprocess.Popen(['ls', '-l'], stdout=subprocess.PIPE)
output = result.communicate()
print(output.decode('utf-8'))
```
2. subprocess.run: This function is a higher-level convenience function introduced in Python 3.5. It is used to run a command and wait for it to complete. It returns a CompletedProcess object that provides information about the completed process, such as return code and output.
Example usage:
```python
import subprocess
# Run a command and get its output
result = subprocess.run(['ls', '-l'], capture_output=True, text=True)
print(result.stdout)
```
Both functions can be used to execute external commands, but the choice between them depends on your requirements. Popen offers more flexibility, while run provides a simpler and more straightforward way to execute commands.
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