Python click option with a prompt AND default hidden

Question

The snippet below prompts for the user and password, and defaults to env variables.

Now while the password input is well hidden while typing, I'd like also to have the default between brackets hidden as well, so far if I enter this, the password default is in clear 1234:

➜  export PASSWORD=1234
➜  python test.py
➜  User [myuser]: you can see here
➜  Password [1234]: 
user you can see here
password you cant see


import os
import click

@click.command()
@click.option('--user', prompt=True, default=lambda: os.environ.get('USER', ''))
@click.option('--password', prompt=True, default=lambda: os.environ.get('PASSWORD', ''), hide_input=True)
def test(user, password):
    print('user {}'.format(user))
    print('password {}'.format(password))
    print(password)


if __name__ == '__main__':
    test()

mVChr · Accepted Answer · 2016-12-21 19:44:14Z

10

You could make a class whose string representation hides the password:

class HiddenPassword(object):
    def __init__(self, password=''):
        self.password = password
    def __str__(self):
        return '*' * len(self.password)

Then in your code you'd just have to check whether this class was used and update the password:

@click.command()
@click.option('--user',
              prompt=True,
              default=lambda: os.environ.get('USER', ''))
@click.option('--password',
              prompt=True,
              default=lambda: HiddenPassword(os.environ.get('PASSWORD', '')),
              hide_input=True)
def test(user, password):
    print('user: {}'.format(user))
    if isinstance(password, HiddenPassword):
        password = password.password
    print('password: {}'.format(password))

In action:

$ PASSWORD=foobar python test.py
User [mVChr]:
Password [******]:
user: mVChr
password: foobar
$ PASSWORD=foobar python test.py
User [mVChr]: dan
Password [******]:
user: dan
password: user-entered-pw

answered Dec 21, 2016 at 19:44

mVChr

50.3k11 gold badges111 silver badges105 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

euri10 Over a year ago

that works well, I just changed to return '*' * 4 so that no info is inferable

mVChr Over a year ago

Good idea, I was being too cutesy. You could even have it return 'env $PASSWORD' or something.

Noam-N Over a year ago

Instead of lambda, use @click.option('--password', prompt=True, hide_input=True, envvar="PASSWORD")

Fabian Hertwig Over a year ago

Unfortunately it does not work for me with click 8.1.3 because I always get a str and not a HiddenPassword instance.

Ilya Luzyanin · Accepted Answer · 2016-12-21 19:38:07Z

3

Could not find a better solution, but maybe this will do. You can use callback for validation to check the input value and replace it to environment value if no input was provided.

def callback(ctx, param, value):
  if not value:
    return os.environ.get('PASSWORD', '')
  return value
...
@click.option('--password', prompt=True, callback=callback, default='', hide_input=True)

answered Dec 21, 2016 at 19:38

Ilya Luzyanin

8,1184 gold badges32 silver badges50 bronze badges

3 Comments

euri10 Over a year ago

I like the solution of @mVChr a little more, the callback works well, I just prefer to display stars, suggesting the user that something is already entered

Ilya Luzyanin Over a year ago

No problem, I like his solution as well :)

mVChr Over a year ago

And I like yours. :) Always a fan of less custom code.

Collectives™ on Stack Overflow

Python click option with a prompt AND default hidden

2 Answers 2

4 Comments

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related