luna.util.file module

create_directory(path, clear=False)[source]

Create the directory pathaname path.

Parameters

  • path (str) – The directory pathname to be created.

  • clear (bool) – If True, clear the directory if already exists. The default value is False.

detect_compression_format(filename)[source]

Attempts to detect compression format from the filename extension. Returns None if no format could be detected.

generate_json_file(json_data, output_file, indent=4, sort_keys=True)[source]

Serialize json_data to a JSON formatted string and save it at output_file.

Parameters

  • json_data (object) – The data to be serialized.

  • output_file (str) – The output file where the serialized data will be saved.

  • indent (int) – If indent is a non-negative integer or string, then JSON array elements and object members will be pretty-printed with that indent level. An indent level of 0, negative, or “” will only insert newlines. None selects the most compact representation. Using a positive integer indent indents that many spaces per level. If indent is a string (such as ” “), that string is used to indent each level. The default value is 4.

  • sort_keys (bool) – If sort_keys is True, the output of dictionaries will be sorted by key.

generic_splitext(path, max_split=None)[source]

Split the pathname path into a pair (filename, ext).

Parameters

  • path (str) – The pathname.

  • max_split (int or None) – Specifies how many splits to do. The default value is None, which is “all occurrences”.

Returns

  • filename (str) – The filename.

  • ext (str) – The file extension.

get_file_format(path, max_split=None, ignore_compression=False)[source]

Detect the file format from pathname path.

Parameters

  • path (str) – The pathname.

  • max_split (int or None) – Specifies how many splits to do. The default value is None, which is “all occurrences”.

  • ignore_compression (bool, optional) – Ignore compression format. The default value is False, which does not ignore compression format.

Returns

filename – The file format.

Return type

str

get_filename(path, max_split=None)[source]

Detect the filename from pathname path.

Parameters

  • path (str) – The pathname.

  • max_split (int or None) – Specifies how many splits to do. The default value is None, which is “all occurrences”.

Returns

filename – The filename.

Return type

str

is_directory_valid(path)[source]

Check if path exists and if it is in fact a directory.

is_file_valid(path)[source]

Check if path exists and if it is in fact a file.

new_unique_filename(path, size=32, chars='ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789', retries=5)[source]

Generate a new unique random pathname.

Parameters

  • path (str) – The target pathname.

  • size (int, optional) – The size of the new filename. The default value is 32.

  • chars (iterable, optional) – A sequence of characters to choose from. The default value is ‘ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789’.

  • retries (int, optional) – The function will keep trying to generate a unique filename (not exist in the pathname path) until the maximum number of retries retries is reached.

Returns

unique_pathname – A new random unique pathname (path + random filename).

Return type

str

parse_json_file(json_file)[source]

Deserialize the JSON file json_file.

Parameters

json_file (str) – The input JSON file.

Returns

json_data – The deserialized data.

Return type

object

pickle_data(data, output_file, compressed=True)[source]

Write the pickled representation of the object data to the file output_file.

Parameters

  • data (object) – The object to be pickled.

  • output_file (str) – The output file where the pickled representation will be saved.

  • compressed (bool, optional) – If True (the default), compress the pickled representation as a gzip file (.gz).

Raises

FileNotCreated – If the file could not be created.

remove_directory(path, only_empty_paths=False)[source]

Remove the directory given by the pathname path.

Parameters

  • path (str) – The pathname.

  • only_empty_paths (bool, optional) – If True, do not remove non-empty directories. The default value is False, which removes all directories.

remove_files(files)[source]

Remove the provided files.

Parameters

files (iterable) – An iterable object containing a sequence of files to be removed.

unpickle_data(input_file)[source]

Read the pickled representation of an object from the file input_file and return the reconstituted object hierarchy specified therein. input_file can be a gzip-compressed file.

Raises

PKLNotReadError – If the file could not be loaded.

validate_directory(path)[source]

Validate path as a directory.

validate_file(path)[source]

Validate path as a file.

validate_filesystem(path, type)[source]

Validate if a file or directory exists and if it has the expected type.

Parameters

  • path (str) – The pathname of the file or directory to be validated.

  • type ({‘file’, ‘directory’}) – The filesystem type.

Raises

  • FileNotFoundError – If the file or directory given by the pathname path does not exist.

  • IsADirectoryError – If a file is provided but a directory is found instead at the pathname path.

  • NotADirectoryError – If the filesystem given by the pathname path is not a directory.