cs.ndjson 20211208

utilities for working with newline delimited JSON (NDJSON) files

Utilities for working with newline delimited JSON (NDJSON) files.

Latest release 20211208: Initial PyPI release.

Function append_ndjson(arg, *a, **kw)

Append an iterable of objects to a file as newline delimited JSON.

Function scan_ndjson(arg, *a, **kw)

Read a newline delimited JSON file, yield instances of dictclass (default dict, otherwise a class which can be instantiated by dictclass(a_dict)).

error_list is an optional list to accrue (lineno,exception) tuples for errors encountered during the scan.

Class UUIDNDJSONMapping(cs.obj.SingletonMixin,cs.mappings.IndexedSetMixin)

A subclass of IndexedSetMixin which maintains records from a newline delimited JSON file.

Method UUIDNDJSONMapping.__init__(self, filename, dictclass=<class 'cs.mappings.UUIDedDict'>, create=False)

Initialise the mapping.

Parameters:

• filename: the file containing the newline delimited JSON data; this need not yet exist
• dictclass: a optional dict subclass to hold each record, default UUIDedDict
• create: if true, ensure the file exists by transiently opening it for append if it is missing; default False

Method UUIDNDJSONMapping.add_backend(self, record)

Append record to the backing file.

Method UUIDNDJSONMapping.rewrite_backend(self)

Rewrite the backing file.

Because the record updates are normally written in append mode, a rewrite will be required every so often.

Method UUIDNDJSONMapping.scan(self)

Scan the backing file, yield records.

Function write_ndjson(arg, *a, **kw)

Transcribe an iterable of objects to a file as newline delimited JSON.

Release Log

Release 20211208: Initial PyPI release.