subprocess.Popen
时间: 2023-10-27 20:57:27 浏览: 23
subprocess.Popen 是 Python 标准库中的一个模块,用于创建一个新的进程并与其交互。它提供了一种在 Python 中调用其他程序的方法。该函数可以接受一些参数,包括要执行的命令和参数、工作目录、环境变量等。可以使用它来执行 shell 命令、运行其他可执行文件等。通过 Popen 对象,可以与子进程进行通信,例如向其发送输入、读取其输出等。
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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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