flashflood.lod

List of dict (LOD) module

List of dict class

class ListOfDict

Bases: list

List of dict utility class

values(key)

Returns record values with the given key

filter(key, value)

Filters by the given key-value pair

find(key, value)

Returns the record found by the given key-value pair. if not found, return None

add(rcd, key='key', dupkey='replace')

Adds a new record.

Duplicate key (dupkey) operations

• replace - replace existing record with the new one (default)
• update - update exisiting record (dict.update)
• skip - add no record when the key is duplicated
• replace or update will be applied for only the first one found

Parameters:

• rcd (dict) – New record to be added
• key (str) – Record key
• dupkey (str) – Type of duplicate key operation

reduce(key='key', dupkey='update')

Removes records with duplicated key

Not appropriate for large data - worst case: O(n^2)

Duplicate key (dupkey) operations

• update - update exisiting record (dict.update)
• skip - add no record when the key is duplicated

Parameters:

• key (str) – Record key
• dupkey (str) – Type of duplicate key operation

unique(key='key')

Aliase of reduce(dupkey=”skip”)

merge(rcds, key='key', dupkey='replace')

Adds list of records

Parameters:

• rcds (list) – List of dict records to be added
• key (str) – Record key
• dupkey (str) – Type of duplicate key operation (see ListOfDict.add)

join(rcds, key, full_join=False)

Left join records

Parameters:

• rcds (list) – List of dict records to be joined
• key (str) – Join key
• full_join (bool) – If true, do full join (join all records regardless of whether key exists)

delete(key, value)

Removes records which matches the key-value pair

Parameters:

• key (str) – key
• value – value

pick(key, value)

Removes a record which matches the key-value pair from the list and return the record.

If no records are found, this returns None.

Parameters:

• key (str) – key
• value – value

LOD = <class 'flashflood.lod.ListOfDict'>

Shorthand of ListOfDict

Non-destructive list of dict functions

valuelist(lod, key)

Returns list of values which are assigned to the key.

Parameters:

• lod – flashflood.lod.ListOfDict
• key – key

Returns:

list of values

Return type:

list

filtered(lod, key, value)

Returns filtered records by the key-value pair.

Parameters:

• key – key
• value – value

Returns:

filtered records

Return type:

flashflood.lod.ListOfDict