Smarter Helper Mixin

class smarter.common.mixins.SmarterHelperMixin(*args, **kwargs)[source]

Bases: object

A generic mixin providing helper functions for Smarter classes.

This mixin offers utility methods and properties commonly needed across Smarter classes, such as:

  • Standardized class name formatting for logging and display

  • URL amnesty lists for exempting certain endpoints from checks

  • JSON and YAML serialization/deserialization utilities

  • Data conversion and dictionary utilities

  • Secure string masking for logging sensitive information

  • Environment variable parsing helpers

  • Fernet encryption key generation

  • File handling utilities for CSV and YAML files

  • Case conversion utilities (snake_case, camelCase, PascalCase, RFC 1034)

Intended Usage:

Inherit this mixin in Smarter classes to gain access to a suite of common helper methods and properties, reducing code duplication and standardizing utility logic.

Examples:

class MyClass(SmarterHelperMixin):
    pass

obj = MyClass()
print(obj.formatted_class_name)
print(obj.data_to_dict('{"foo": "bar"}'))
print(obj.mask_string("my-secret-key"))

Main Features:

  • formatted_class_name: Returns the class name formatted for logging.

  • amnesty_urls: List of URL paths exempt from certain checks.

  • deserves_amnesty(slug): Checks if a URL deserves amnesty.

  • smarter_build_absolute_uri(request): Safely builds an absolute URI from a Django HttpRequest.

  • mask_string(...): Masks sensitive strings for secure logging.

  • bool_environment_variable(var_name, default): Parses environment variables as booleans.

  • generate_fernet_encryption_key(): Generates a Fernet encryption key.

  • data_to_dict(data): Converts JSON/YAML string or dict to dict.

  • sorted_dict(data): Returns a sorted copy of a dictionary.

  • dict_is_contained_in(dict1, dict2): Checks if one dict is contained in another.

  • dict_is_subset(small, big): Checks if one dict is a subset of another.

  • recursive_sort_dict(data): Recursively sorts a dictionary.

  • get_readonly_csv_file(file_path): Opens a CSV file in read-only mode.

  • get_readonly_yaml_file(file_path): Opens a YAML file in read-only mode.

  • Case conversion utilities: to_snake_case, to_snake_case, to_snake_case, snake_case, to_camel_case, to_snake_case, rfc1034_compliant_str, rfc1034_compliant_to_snake.

__init__(*args, **kwargs)[source]

Note: this needs to exist.

something in the Python MRO requires it, even if it does nothing. If you remove this, you will get a mysterious error about something downstream expecting exactly one object.

property amnesty_urls: list[str][source]

Returns a list of URLs that are exempt from certain checks.

Returns:

List of URL path strings that are exempt.

Return type:

list[str]

bool_environment_variable(var_name, default=False)[source]

Retrieves a boolean value from an environment variable.

This method checks the specified environment variable and returns its value as a boolean. It recognizes common truthy values such as “true”, “1”, “yes”, and “on”. If the variable is not set or cannot be interpreted as a boolean, it returns the provided default value.

Parameters:
  • var_name (str) – The name of the environment variable to check.

  • default (bool) – The default boolean value to return if the environment variable is not set or invalid.

Returns:

The boolean value of the environment variable or the default.

Return type:

bool

data_to_dict(data)[source]

Converts data to a dictionary, handling different types of input.

This method accepts either a dictionary or a string. If a string is provided, it will attempt to parse it as JSON first, and if that fails, as YAML. If parsing fails or the data type is unsupported, a SmarterValueError is raised.

Parameters:

data (Union[dict, str]) – The data to convert, either a dict or a JSON/YAML string.

Returns:

The data as a dictionary.

Return type:

dict

Raises:

SmarterValueError – If the data cannot be converted to a dictionary.

deserves_amnesty(slug)[source]

Determines if a given URL deserves amnesty based on the amnesty URLs list.

This excuses certain endpoints (like health checks) from select middleware checks.

Parameters:

slug (str) – The URL path to check.

Returns:

True if the URL deserves amnesty, False otherwise.

Return type:

bool

dict_is_contained_in(dict1, dict2)[source]

Checks if one dictionary is contained within another.

This method determines if all key-value pairs in dict1 are present in dict2.

Parameters:
  • dict1 (dict) – The dictionary to check for containment.

  • dict2 (dict) – The dictionary to check against for containment.

Returns:

True if dict1 is contained in dict2, False otherwise.

Return type:

bool

dict_is_subset(small, big)[source]

Checks if one dictionary is a subset of another.

This method determines if all key-value pairs in the small dictionary are present in the big dictionary. It returns True if the small dictionary is a subset of the big dictionary, and False otherwise.

Parameters:
  • small (dict) – The dictionary to check as a subset.

  • big (dict) – The dictionary to check against as a superset.

Returns:

True if the small dictionary is a subset of the big dictionary, False otherwise.

Return type:

bool

property formatted_class_name: str[source]

Returns the class name formatted for logging.

Returns:

The formatted class name as a string.

Return type:

str

formatted_json(json_obj)[source]

Formats a JSON object as a pretty-printed string with ANSI color codes for logging.

Parameters:

json_obj (Union[dict, list]) – The JSON object (dict or list) to format.

Returns:

A string representation of the JSON object with ANSI color codes.

Return type:

str

property formatted_state_not_ready: str[source]

Returns the not-ready state formatted for logging.

Returns:

The formatted not-ready state as a string.

Return type:

str

property formatted_state_ready: str[source]

Returns the readiness state formatted for logging.

Returns:

The formatted readiness state as a string.

Return type:

str

formatted_text(text, color_code='\\x1b[1;31m')[source]

Formats text with ANSI color codes for logging.

Parameters:
  • text (str) – The text to format.

  • color_code (str) – The ANSI color code to apply.

Returns:

The formatted text with ANSI color codes.

Return type:

str

formatted_text_blue(text)[source]

Formats text in bold dark blue for logging.

Parameters:

text (str) – The text to format.

Returns:

The formatted text in bold dark blue.

Return type:

str

formatted_text_green(text)[source]

Formats text in bright green for logging.

Parameters:

text (str) – The text to format.

Returns:

The formatted text in bright green.

Return type:

str

formatted_text_red(text)[source]

Formats text in dark red for logging.

Parameters:

text (str) – The text to format.

Returns:

The formatted text in dark red.

Return type:

str

generate_fernet_encryption_key()[source]

Generates a Fernet encryption key.

This method creates a new Fernet encryption key, which can be used for secure encryption and decryption of data. The generated key is returned as a URL-safe base64-encoded string.

Returns:

A new Fernet encryption key.

Return type:

str

get_readonly_csv_file(file_path)[source]

Retrieves a read-only file object for a CSV file.

This method opens the specified CSV file in read-only mode and returns a file object that can be used to read its contents. It ensures that the file is not modified during the reading process.

Parameters:

file_path (str) – The path to the CSV file to open.

Returns:

A read-only file object for the specified CSV file.

Return type:

file

get_readonly_yaml_file(file_path)[source]

Retrieves a read-only file object for a YAML file.

This method opens the specified YAML file in read-only mode and returns a file object that can be used to read its contents. It ensures that the file is not modified during the reading process.

Parameters:

file_path (str) – The path to the YAML file to open.

Returns:

A read-only file object for the specified YAML file.

Return type:

file

property health_check_urls: list[str][source]

Returns a list of URL paths that are considered health check endpoints.

Returns:

List of health check URL path strings.

Return type:

list[str]

mask_string(string='', mask_char='*', mask_length=4, string_length=8)[source]

Masks a string for secure logging.

This utility function masks all but the last unmasked_chars characters of the input string, replacing them with asterisks. It is useful for logging sensitive information like API keys or passwords.

Parameters:
  • string (Optional[str]) – The string to be masked.

  • mask_char (str) – The character used for masking.

  • mask_length (int) – The number of characters to mask.

  • string_length (int) – The length of the string to consider for masking.

Returns:

The masked string.

Return type:

str

property ready: bool

Indicates whether the object is ready for use.

This is a placeholder that should be overridden in subclasses.

Returns:

True if ready, False otherwise.

Return type:

bool

recursive_sort_dict(data)[source]

Recursively sorts a dictionary by its keys.

This method takes a dictionary and returns a new dictionary with all keys sorted in ascending order. If any values are also dictionaries, they will be sorted recursively as well.

Parameters:

data (dict) – The dictionary to sort.

Returns:

A new dictionary with all keys sorted.

Return type:

dict

rfc1034_compliant_str(name)[source]

Converts a string to an RFC 1034 compliant format.

This method takes a string and converts it to a format that complies with RFC 1034, which is commonly used for domain names. It replaces invalid characters with hyphens and ensures the resulting string is lowercase.

Parameters:

name (str) – The string to convert to RFC 1034 compliant format.

Returns:

The converted string in RFC 1034 compliant format.

Return type:

str

rfc1034_compliant_to_snake(name)[source]

Converts an RFC 1034 compliant string to snake_case.

This method takes a string in RFC 1034 compliant format and converts it to snake_case. It replaces hyphens with underscores and ensures the resulting string is lowercase.

Parameters:

name (str) – The RFC 1034 compliant string to convert.

Returns:

The converted string in snake_case.

Return type:

str

smarter_build_absolute_uri(request)[source]

Attempts to get the absolute URI from a request object.

This utility function tries to retrieve the request URL from any valid child class of django.http.HttpRequest. It is especially useful in unit tests or scenarios where the request object may not implement build_absolute_uri().

Parameters:

request (HttpRequest) – The request object.

Returns:

The absolute request URL.

Return type:

Optional[str]

Raises:

SmarterValueError – If the URI cannot be built from the request.

sorted_dict(data)[source]

Returns a new dictionary with keys sorted.

Parameters:

data (dict) – The dictionary to sort.

Returns:

A new dictionary with sorted keys.

Return type:

dict

to_camel_case(data, convert_values=False)[source]

Converts a snake_case string to camelCase.

This method takes a string in snake_case format and converts it to camelCase. It is useful for standardizing naming conventions across different formats.

Parameters:
  • data (Union[str, dict[str, object], list[object], object]) – The snake_case string to convert.

  • convert_values (bool) – Whether to convert the values of dictionaries and lists recursively.

Returns:

The converted string in camelCase.

Return type:

Any

to_snake_case(data, convert_values=False)[source]

Converts a camelCase or PascalCase string to snake_case.

This method takes a string in camelCase or PascalCase format and converts it to snake_case. It is useful for standardizing naming conventions across different formats.

Parameters:
  • data (Union[str, dict[str, object], list[object], object]) – The camelCase or PascalCase string to convert.

  • convert_values (bool) – Whether to convert the values of dictionaries and lists recursively.

Returns:

The converted string in snake_case.

Return type:

Any

property unformatted_class_name: str[source]

Returns the raw class name without formatting.

Returns:

The unformatted class name as a string.

Return type:

str

This is useful for logging or serialization where the plain class name is needed.