shell.py 文件源码

def setenv(self, key, val):
        """
        Set internal environment variable.

        Changes internal environment in which subprocesses will be run.
        Does not change the process's own environment.

        :param key: name of variable
        :param value: value of variable
        """
        if val is None:
            if key in self._env:
                del self._env[key]
            return
        key = str(key)  # keys must be strings
        val = str(val)  # vals must be strings
        self._env[key] = val