Examples

hello_wexpect.py

This is the simplest example. It starts a windows command interpreter (aka. cmd) lists the current directory and exits.

import wexpect

# Start cmd as child process
child = wexpect.spawn('cmd.exe')

# Wait for prompt when cmd becomes ready.
child.expect('>')

# Prints the cmd's start message
print(child.before, end='')
print(child.after, end='')

# run list directory command
child.sendline('ls')

# Waiting for prompt
child.expect('>')

# Prints content of the directory
print(child.before, end='')
print(child.after, end='')

# Exit from cmd
child.sendline('exit')

# Waiting for cmd termination.
child.wait()

terminaton.py

This script shows three method to terminate your application. terminate_programmatically() shows the recommended way, which kills the child by sending the application specific exit command. After that waiting for the terminaton is recommended. terminate_eof() shows how to terminate child program by sending EOF character. Some program can be terminated by sending EOF character. Waiting for the terminaton is recommended in this case too. terminate_terminate() shows how to terminate child program by sending kill signal. Some application requires sending SIGTERM to kill the child process. terminate() call kill() function, which sends SIGTERM to child process. Waiting for the terminaton is not required explicitly in this case. The wait is included in terminate() function.

import wexpect

def terminate_programmatically():
    '''Terminate child program by command. This is the recommended method. Send your application's
    exit command to quit the child's process. After that wait for the terminaton.
    '''
    print('terminate_programmatically')

    # Start cmd as child process
    child = wexpect.spawn('cmd.exe')

    # Wait for prompt when cmd becomes ready.
    child.expect('>')

    # Exit from cmd
    child.sendline('exit')

    # Waiting for cmd termination.
    child.wait()

def terminate_eof():
    '''Terminate child program by sending EOF character. Some program can be terminated by sending
    an EOF character. Waiting for the terminaton is recommended in this case too.
    '''
    print('terminate_eof')

    # Start cat as child process
    child = wexpect.spawn('cat')

    # Exit by sending EOF
    child.sendeof()

    # Waiting for cmd termination.
    child.wait()


def terminate_terminate():
    '''Terminate child program by sending kill signal. Some application requires sending SIGTERM to kill
    the child process. `terminate()` call `kill()` function, which sends SIGTERM to child process.
    Waiting for the terminaton is not required explicitly in this case. The wait is included in
    `terminate()` function.
    '''
    print('terminate_terminate')

    # Start cmd as child process
    child = wexpect.spawn('cmd.exe')

    # Wait for prompt when cmd becomes ready.
    child.expect('>')

    # Exit from cmd
    child.terminate()


terminate_programmatically()
terminate_eof()
terminate_terminate()