[FIXED] Hide variable (e.g. 'password') from print and call of pydantic data model

Issue

I am using pydantic for some user/password data model. When the model is printed, I want to replace the value of password with something else (*** for example) to prevent that the password is e.g. written into log-files or the console accidentally.

from pydantic import BaseModel

class myUserClass(BaseModel):
    User = 'foo'
    Password = 'bar'

    def __str__(self):
        return "Hidden parameters."

U = myUserClass()

print(U)
# > Hidden parameters. # Should be User='foo', Password='***' or similar

U # This will still show my password.
#> myUserClass(User='foo', Password='bar')

How can I access the string that is normally printed and replace only 'bar' with '***', but keeping all parameters?

How can I also do that when just calling U? This may not be equally important as for logging and console output usually print is called.

Solution

Pydantic provides SecretStr data type. Which is replaced by *** when converted to str (e.g printed) and actual value can be obtained by get_secret_value() method:

class Foobar(BaseModel):
    password: SecretStr
    empty_password: SecretStr

# Initialize the model.
f = Foobar(password='1234', empty_password='')


# Assert str and repr are correct.
assert str(f.password) == '**********'
assert str(f.empty_password) == ''

# Assert retrieval of secret value is correct
assert f.password.get_secret_value() == '1234'
assert f.empty_password.get_secret_value() == ''

Answered By - alex_noname