Automatically answer yes on pythons click prompts unattended command run

When running a Python script that requires user input through click prompts, it can be tedious to manually answer each prompt, especially when running the script unattended. In this article, we will explore three different ways to automatically answer “yes” to these prompts, allowing for unattended command runs.

Solution 1: Using the subprocess module

The subprocess module in Python provides a way to spawn new processes, connect to their input/output/error pipes, and obtain their return codes. We can leverage this module to automatically answer “yes” to click prompts.

import subprocess

def run_script():
    process = subprocess.Popen(['python', 'script.py'], stdin=subprocess.PIPE)
    process.communicate(input=b'yesn')

In this solution, we use the subprocess.Popen function to spawn a new process and connect to its input pipe. We pass the command to run the script as a list of arguments, where the first argument is the Python interpreter and the second argument is the script file. We also specify stdin=subprocess.PIPE to redirect the standard input of the process to a pipe.

Next, we use the process.communicate method to send the input to the process. In this case, we send the string “yes” followed by a newline character to simulate the user input. The communicate method returns a tuple containing the output and error streams of the process, but since we are not interested in capturing them, we don’t assign them to any variables.

Solution 2: Using the pexpect module

The pexpect module is a Python module for spawning child applications and controlling them automatically. It provides a higher-level interface compared to the subprocess module, making it easier to automate interactive command-line programs.

import pexpect

def run_script():
    child = pexpect.spawn('python script.py')
    child.expect('prompt:')
    child.sendline('yes')

In this solution, we use the pexpect.spawn function to spawn a new process and connect to it. We pass the command to run the script as a string. The spawn function returns a child process object.

Next, we use the child.expect method to wait for a specific prompt from the script. Once the prompt is detected, we use the child.sendline method to send the input “yes” to the script.

Solution 3: Modifying the script

If you have access to the script that requires user input, another option is to modify the script itself to automatically answer “yes” to the prompts. This can be done by adding a conditional statement that checks if the script is running in an unattended mode and automatically answers “yes” to the prompts.

import sys

def run_script():
    unattended_mode = True  # Set this flag to True when running unattended
    if unattended_mode:
        sys.stdin = open('/dev/null')  # Redirect standard input to /dev/null
    # Rest of the script

In this solution, we add a flag unattended_mode that can be set to True when running the script unattended. If the flag is set to True, we redirect the standard input to /dev/null using sys.stdin = open('/dev/null'). This effectively discards any input from the user, simulating an automatic “yes” response.

After implementing the desired solution, you can use the run_script function to execute the script with automatic “yes” responses to click prompts.

Among the three options, Solution 2 using the pexpect module provides a more streamlined and intuitive approach for automating interactive command-line programs. It offers a higher-level interface and simplifies the process of waiting for specific prompts and sending input. Therefore, Solution 2 is the recommended option for automatically answering “yes” on Python’s click prompts during unattended command runs.

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5 Responses

    1. Ive used pexpect extensively and its been great for handling various prompts. Its flexible and can handle different prompt types efficiently. Give it a try and see for yourself.

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