import os
import abc


class Credential(metaclass=abc.ABCMeta):
    """Abstract class to manage credentials"""

    @abc.abstractproperty
    def username(self):
        return None

    @abc.abstractproperty
    def password(self):
        return None


class SimpleCredential(Credential):
    """Simple credentials implementation"""

    def __init__(self, username, password):
        self._username = username
        self._password = password

    @property
    def username(self):
        return self._username

    @property
    def password(self):
        return self._password


class EnvironCredential(Credential):
    """Source credentials from environment variables.
    Actual sourcing is deferred until requested.
    """

    def __init__(self, user_env_var, pwd_env_var):
        self.user_env_var = user_env_var
        self.pwd_env_var = pwd_env_var

    def _get_env(self, env_var):
        """Helper to read an environment variable"""
        value = os.environ.get(env_var)
        if not value:
            raise ValueError('Missing environment variable:%s' % env_var)
        return value

    @property
    def username(self):
        return self._get_env(self.user_env_var)

    @property
    def password(self):
        return self._get_env(self.pwd_env_var)

import os
import abc


class Credential(metaclass=abc.ABCMeta):
    """Abstract class to manage credentials"""

    @abc.abstractproperty
    def username(self):
        return None

    @abc.abstractproperty
    def password(self):
        return None


class SimpleCredential(Credential):
    """Simple credentials implementation"""

    def __init__(self, username, password):
        self._username = username
        self._password = password

    @property
    def username(self):
        return self._username

    @property
    def password(self):
        return self._password


class EnvironCredential(Credential):
    """Source credentials from environment variables.
    Actual sourcing is deferred until requested.
    """

    def __init__(self, user_env_var, pwd_env_var):
        self.user_env_var = user_env_var
        self.pwd_env_var = pwd_env_var

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, EnvironCredential):
            return NotImplemented

        return (
            self.user_env_var == other.user_env_var
            and self.pwd_env_var == other.pwd_env_var
        )

    def _get_env(self, env_var):
        """Helper to read an environment variable"""
        value = os.environ.get(env_var)
        if not value:
            raise ValueError('Missing environment variable:%s' % env_var)
        return value

    @property
    def username(self):
        return self._get_env(self.user_env_var)

    @property
    def password(self):
        return self._get_env(self.pwd_env_var)

Add equality operator to EnvironCredential
Add equality operator to EnvironCredential

Equality operator is useful for testing EnvironCredential

  import os
  import abc
  
  
  class Credential(metaclass=abc.ABCMeta):
      """Abstract class to manage credentials"""
  
      @abc.abstractproperty
      def username(self):
          return None
  
      @abc.abstractproperty
      def password(self):
          return None
  
  
  class SimpleCredential(Credential):
      """Simple credentials implementation"""
  
      def __init__(self, username, password):
          self._username = username
          self._password = password
  
      @property
      def username(self):
          return self._username
  
      @property
      def password(self):
          return self._password
  
  
  class EnvironCredential(Credential):
      """Source credentials from environment variables.
      Actual sourcing is deferred until requested.
      """
  
      def __init__(self, user_env_var, pwd_env_var):
          self.user_env_var = user_env_var
          self.pwd_env_var = pwd_env_var
  
+     def __eq__(self, other: object) -> bool:
+         if not isinstance(other, EnvironCredential):
+             return NotImplemented
+ 
+         return (
+             self.user_env_var == other.user_env_var
+             and self.pwd_env_var == other.pwd_env_var
+         )
+ 
      def _get_env(self, env_var):
          """Helper to read an environment variable"""
          value = os.environ.get(env_var)
          if not value:
              raise ValueError('Missing environment variable:%s' % env_var)
          return value
  
      @property
      def username(self):
          return self._get_env(self.user_env_var)
  
      @property
      def password(self):
          return self._get_env(self.pwd_env_var)
  
Add equality operator to EnvironCredential
## Code Before:
import os
import abc


class Credential(metaclass=abc.ABCMeta):
    """Abstract class to manage credentials"""

    @abc.abstractproperty
    def username(self):
        return None

    @abc.abstractproperty
    def password(self):
        return None


class SimpleCredential(Credential):
    """Simple credentials implementation"""

    def __init__(self, username, password):
        self._username = username
        self._password = password

    @property
    def username(self):
        return self._username

    @property
    def password(self):
        return self._password


class EnvironCredential(Credential):
    """Source credentials from environment variables.
    Actual sourcing is deferred until requested.
    """

    def __init__(self, user_env_var, pwd_env_var):
        self.user_env_var = user_env_var
        self.pwd_env_var = pwd_env_var

    def _get_env(self, env_var):
        """Helper to read an environment variable"""
        value = os.environ.get(env_var)
        if not value:
            raise ValueError('Missing environment variable:%s' % env_var)
        return value

    @property
    def username(self):
        return self._get_env(self.user_env_var)

    @property
    def password(self):
        return self._get_env(self.pwd_env_var)

## Instruction:
Add equality operator to EnvironCredential
## Code After:
import os
import abc


class Credential(metaclass=abc.ABCMeta):
    """Abstract class to manage credentials"""

    @abc.abstractproperty
    def username(self):
        return None

    @abc.abstractproperty
    def password(self):
        return None


class SimpleCredential(Credential):
    """Simple credentials implementation"""

    def __init__(self, username, password):
        self._username = username
        self._password = password

    @property
    def username(self):
        return self._username

    @property
    def password(self):
        return self._password


class EnvironCredential(Credential):
    """Source credentials from environment variables.
    Actual sourcing is deferred until requested.
    """

    def __init__(self, user_env_var, pwd_env_var):
        self.user_env_var = user_env_var
        self.pwd_env_var = pwd_env_var

    def __eq__(self, other: object) -> bool:
        if not isinstance(other, EnvironCredential):
            return NotImplemented

        return (
            self.user_env_var == other.user_env_var
            and self.pwd_env_var == other.pwd_env_var
        )

    def _get_env(self, env_var):
        """Helper to read an environment variable"""
        value = os.environ.get(env_var)
        if not value:
            raise ValueError('Missing environment variable:%s' % env_var)
        return value

    @property
    def username(self):
        return self._get_env(self.user_env_var)

    @property
    def password(self):
        return self._get_env(self.pwd_env_var)
