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Manage environment variables in Python with `os.putenv()` for better control over script behavior.

# Python os.putenv Usage

The `os.putenv()` function in Python is used to set an environment variable `varname` to the specified `value`. This affects child processes as well. Below is an explanation and examples of how to use `os.putenv()` in Python.

### Explanation

The `os.putenv(varname, value)` function is part of the `os` module in Python. It allows you to modify the environment variables for the current process and any child processes that are spawned. By setting environment variables, you can control various aspects of how your Python scripts interact with the operating system and other programs.

### Examples

Here are some examples to demonstrate the usage of `os.putenv()`:

“`python
# Setting the environment variable ‘test’ to ‘\\tmp\\test’
from os import putenv

putenv(‘test’, ‘\\tmp\\test’)

# Checking the effect on a child process
from os import popen

p = popen(”’python -c “import os; print(os.getenv(‘test’))””’, ‘r’)
print(p.read())
“`

In the above example, we first set the environment variable `test` to `\\tmp\\test` using `putenv()`. Then, we spawn a child process using `popen()` to check if the child process can access the updated environment variable. The child process prints the value of the `test` environment variable, which should reflect the change we made using `putenv()`.

### Conclusion

`os.putenv()` is a useful function in Python for managing environment variables within your scripts. By using this function, you can control the behavior of your Python programs in relation to the operating system and other processes. Make sure to use it wisely and consider the implications of changing environment variables in your scripts.