Module Contents

class weaver.utils._Singleton[source]

Bases: type

class weaver.utils._NullType[source]

Bases: six.with_metaclass()

Represents a null value to differentiate from None.

weaver.utils.get_weaver_url(container) → AnyStr[source]

Retrieves the home URL of the weaver application.

weaver.utils.get_any_id(info) → Union[AnyStr, None][source]

Retrieves a dictionary id-like key using multiple common variations [id, identifier, _id]. :param info: dictionary that potentially contains an id-like key. :returns: value of the matched id-like key or None if not found.

weaver.utils.get_any_value(info) → AnyValue[source]

Retrieves a dictionary value-like key using multiple common variations [href, value, reference]. :param info: dictionary that potentially contains a value-like key. :returns: value of the matched value-like key or None if not found.

weaver.utils.get_any_message(info) → AnyStr[source]

Retrieves a dictionary ‘value’-like key using multiple common variations [message]. :param info: dictionary that potentially contains a ‘message’-like key. :returns: value of the matched ‘message’-like key or an empty string if not found.

weaver.utils.get_registry(container) → Registry[source]

Retrieves the application registry from various containers referencing to it.

weaver.utils.get_settings(container) → SettingsType[source]

Retrieves the application settings from various containers referencing to it.

weaver.utils.get_header(header_name, header_container) → Union[AnyStr, None][source]

Searches for the specified header by case/dash/underscore-insensitive header_name inside header_container.

Looks for cookie_header_name header within header_container. :returns: new header container in the form {'Cookie': <found_cookie>} if it was matched, or empty otherwise.

weaver.utils.get_url_without_query(url) → AnyStr[source]

Removes the query string part of an URL.

weaver.utils.is_valid_url(url) → bool[source]

Parses the extra options parameter.

The option_str is a string with coma separated opt=value pairs. Example:

Parameters:option_str – A string parameter with the extra options.
Returns:A dict with the parsed extra options.
weaver.utils.fully_qualified_name(obj) → str[source]

Obtains the '<module>.<name>' full path definition of the object to allow finding and importing it.

weaver.utils.now() → datetime[source]
weaver.utils.now_secs() → int[source]

Return the current time in seconds since the Epoch.

weaver.utils.expires_at(hours=1) → int[source]
weaver.utils.localize_datetime(dt, tz_name='UTC') → datetime[source]

Provide a timezone-aware object for a given datetime and timezone name

weaver.utils.get_base_url(url) → AnyStr[source]

Obtains the base URL from the given url.

weaver.utils.xml_path_elements(path) → List[AnyStr][source]
weaver.utils.xml_strip_ns(tree) → None[source]
weaver.utils.ows_context_href(href, partial=False) → JSON[source]

Returns the complete or partial dictionary defining an OWSContext from a reference.

weaver.utils.pass_http_error(exception, expected_http_error) → None[source]

Given an HTTPError of any type (pyramid, requests), ignores (pass) the exception if the actual error matches the status code. Other exceptions are re-raised.

  • exception – any Exception instance (“object” from a try..except exception as “object” block).
  • expected_http_error – single or list of specific pyramid HTTPError to handle and ignore.

exception – if it doesn’t match the status code or is not an HTTPError of any module.


Raises an exception with the description if the XML response document defines an ExceptionReport. :param xml_node: instance of etree.Element :raise Exception: on found ExceptionReport document.

weaver.utils.str2bytes(string) → bytes[source]

Obtains the bytes representation of the string.

weaver.utils.bytes2str(string) → str[source]

Obtains the unicode representation of the string.

weaver.utils.islambda(func) → bool[source]
weaver.utils.convert_snake_case(name) → AnyStr[source]
weaver.utils.parse_request_query(request) → Dict[AnyStr, Dict[AnyKey, AnyStr]][source]
Returns:dict of dict where k=v are accessible by d[k][0] == v and q=k=v are accessible by d[q][k] == v, lowercase
weaver.utils.get_log_fmt() → AnyStr[source]
weaver.utils.get_log_date_fmt() → AnyStr[source]
weaver.utils.get_log_monitor_msg(job_id, status, percent, message, location) → AnyStr[source]
weaver.utils.get_job_log_msg(status, message, progress=0, duration=None) → AnyStr[source]
weaver.utils.make_dirs(path, mode=493, exist_ok=False)[source]

Alternative to os.makedirs with exists_ok parameter only available for python>3.5. Also using a reduced set of permissions 755 instead of original default 777.


The method employed in this function is safer then if os.pat.exists or if os.pat.isdir pre-check to calling os.makedirs as this can result in race condition (between evaluation and actual creation).

weaver.utils.get_caller_name(skip=2, base_class=False)[source]

Returns the name of a caller in the format module.class.method.

  • skip – specifies how many levels of stack to skip while getting the caller.
  • base_class – Specified if the base class should be returned or the top-most class in case of inheritance If the caller is not a class, this doesn’t do anything.

An empty string if skipped levels exceed stack height; otherwise, the requested caller name.

weaver.utils.get_ssl_verify_option(method, url, settings, request_options=None) → bool[source]

Obtains the SSL verification option from combined settings from weaver.ssl_verify and parsed weaver.request_options file for the corresponding request.

  • method – request method (GET, POST, etc.).
  • url – request URL.
  • settings – application setting container with pre-loaded request options specifications.
  • request_options – pre-processed request options for method/URL to avoid re-parsing the settings.

SSL verify option to be passed down to some request function.

weaver.utils.get_request_options(method, url, settings) → SettingsType[source]

Obtains the request options corresponding to the request according to configuration file specified by pre-loaded setting weaver.request_options.

If no file was pre-loaded or no match is found for the request, an empty options dictionary is returned.

  • method – request method (GET, POST, etc.).
  • url – request URL.
  • settings – application setting container with pre-loaded request options specifications.

dictionary with keyword options to be applied to the corresponding request if matched.

weaver.utils.request_extra(method, url, retries=None, backoff=None, intervals=None, retry_after=True, allowed_codes=None, only_server_errors=True, ssl_verify=None, settings=None, **request_kwargs) → AnyResponseType[source]

Standard library requests with additional functional utilities.

Implements request retry if the previous request failed, up to the specified number of retries. Using :paramref:`backoff` factor, you can control the interval between request attempts such as:

delay = backoff * (2 ^ retry)

Alternatively, you can explicitly define intervals=[...] with the list values being the number of seconds to wait between each request attempt. In this case, :paramref:`backoff` is ignored and :paramref:`retries` is overridden accordingly with the number of items specified in the list.

Furthermore, :paramref:`retry_after` (default: True) indicates if HTTP status code 429 (Too Many Requests) should be automatically handled during retries. If enabled and provided in the previously failed request response through the Retry-After header, the next request attempt will be executed only after the server-specified delay instead of following the calculated delay from :paramref:`retries` and :paramref:`backoff`, or from corresponding index of :paramref:`interval`, accordingly to specified parameters. This will avoid uselessly calling the server and automatically receive a denied response. You can disable this feature by passing False, which will result into requests being retried blindly without consideration of the called server instruction.

Because different request implementations use different parameter naming conventions, all following keywords are looked for:

  • Both variants of backoff and backoff_factor are accepted.
  • All variants of retires, retry and max_retries are accepted.


Total amount of executed request attempts will be +1 the number of :paramref:`retries` or :paramref:`intervals` items as first request is done immediately, and following attempts are done with the appropriate delay.

Any request with file:// scheme or empty scheme (no scheme specified) will be automatically handled as potential local file path. The path should be absolute to ensure it to be correctly resolved.

All access errors due to file permissions return 403 status code, and missing file returns 404. Any other IOError types are converted to a 400 responses.

See also

  • FileAdapter

Allows SSL verify option to be enabled or disabled according to configuration settings or explicit parameters. Any variation of verify or ssl_verify keyword arguments are considered. If they all resolve to True, then application settings are retrieved from weaver.ini to parse additional SSL options that could disable it.

Following weaver settings are considered :
  • weaver.ssl_verify = True|False
  • weaver.request_options = request_options.yml


Argument :paramref:`settings` must also be provided through any supported container by get_settings() to retrieve and apply any weaver-specific configurations.

  • method – HTTP method to set request.
  • url – URL of the request to execute.
  • retries – Number of request retries to attempt if first attempt failed (according to allowed codes or error).
  • backoff – Factor by which to multiply delays between retries.
  • intervals – Explicit intervals in seconds between retries.
  • retry_after – If enabled, honor Retry-After response header of provided by a failing request attempt.
  • allowed_codes – HTTP status codes that are considered valid to stop retrying (default: any non-4xx/5xx code).
  • ssl_verify – Explicit parameter to disable SSL verification (overrides any settings, default: True).
  • settings – Additional settings from which to retrieve configuration details for requests.
  • only_server_errors – Only HTTP status codes in the 5xx values will be considered for retrying the request (default: True). This catches sporadic server timeout, connection error, etc., but 4xx errors are still considered valid results. This parameter is ignored if allowed codes are explicitly specified.
  • request_kwargs – All other keyword arguments are passed down to the request call.
weaver.utils.fetch_file(file_reference, file_outdir, settings=None, **request_kwargs) → AnyStr[source]

Fetches a file from a local path or remote URL and dumps it’s content to the specified output directory.

The output directory is expected to exist prior to this function call.

  • file_reference – Local filesystem path or remote URL file reference.
  • file_outdir – Output directory path of the fetched file.
  • settings – Additional request setting details from the application configuration.
  • request_kwargs – Additional keywords to forward to request call (if needed).

Path of the local copy of the fetched file.

weaver.utils.get_sane_name(name, min_len=3, max_len=None, assert_invalid=True, replace_character='_') → Union[AnyStr, None][source]

Returns a cleaned-up version of the input name, replacing invalid characters matched with REGEX_SEARCH_INVALID_CHARACTERS by replace_character.

  • name – value to clean
  • min_len – Minimal length of name to be respected, raises or returns None on fail according to assert_invalid.
  • max_len – Maximum length of name to be respected, raises or returns trimmed name on fail according to assert_invalid. If None, condition is ignored for assertion or full name is returned respectively.
  • assert_invalid – If True, fail conditions or invalid characters will raise an error instead of replacing.
  • replace_character – Single character to use for replacement of invalid ones if assert_invalid=False.
weaver.utils.assert_sane_name(name, min_len=3, max_len=None)[source]

Asserts that the sane name respects conditions.

See also

weaver.utils.clean_json_text_body(body) → AnyStr[source]

Cleans a textual body field of superfluous characters to provide a better human-readable text in a JSON response.