<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def chdir(directory):
 """Change the current working directory to a different directory for a code block and return the previous directory after the block exits. Useful to run commands from a specificed directory. :param str directory: The directory path to change to for this context. """

    cur = os.getcwd()
    try:
        yield os.chdir(directory)
    finally:
        os.chdir(cur)