How can I evaluate if a env variable is a boolean True, in Python? Is it correct to use:

if os.environ['ENV_VAR'] is True:
      .......

Option 1

I think this works well:

my_env = os.getenv("ENV_VAR", 'False').lower() in ('true', '1', 't')

It allows: things like true, True, TRUE, 1, "1", TrUe, t, T, ...

Update: After I read the commentary of Klaas, I updated the original code my_env = bool(os.getenv(... to my_env = os.getenv(... because in will result in a bool type

Option 2

UPDATE: After the @MattG commentary, I added a new solution that raises an error for entries like ttrue instead of returning False:

# ...
import os
# ...

TRUTHY_VALUES = ('true', '1', 't')  # Add more entries if you want, like: `y`, `yes`, `on`, ...
FALSY_VALUES = ('false', '0', 'f')  # Add more entries if you want, like: `n`, `no`, `off`, ...
VALID_VALUES = TRUTHY_VALUES + FALSY_VALUES

def get_bool_env_variable(name: str, default_value: bool | None = None) -> bool:
    value = os.getenv(name) or default_value
    if value is None:
        raise ValueError(f'Environment variable "{name}" is not set!')
    value = str(value).lower()
    if value not in VALID_VALUES:
        raise ValueError(f'Invalid value "{value}" for environment variable "{name}"!')
    return value in TRUTHY_VALUES

# ...

my_env1 = get_bool_env_variable('ENV_VAR1') # Raise error if variable was not set
my_env2 = get_bool_env_variable('ENV_VAR2', default_value=False) # return False if variable was not set