CODEWITHSUNDEEP
python
AP70
AP70

Reputation: 103

How to retrieve dicts from a list of dicts using wildcard key value

I have a large list of dictionaries, each dict has a key:value as normal. I want to grab all dicts that a match a particular wildcard key value for the name key in the example below.

For example, if the values of the name keys below are in the format A_B_C_D (e.g. John_Michael_Joseph_Smith), how would I grab all dicts searching for name values of format A*D (e.g. John*Smith?) Or format A_B* (e.g. John_Michael*) etc?

mylist=[{id:value,name:value,parent:value},
        {id:value,name:value,parent:value},
        {id:value,name:value,parent:value}...]

Upvotes: 0

Views: 986

Answers (1)

Martijn Pieters
Martijn Pieters

Reputation: 1122122

Your patterns appear to use UNIX filename patterns; * matching any number of characters. You can use the fnmatch.fnmatch() function to produce a filter:

>>> from fnmatch import fnmatch
>>> fnmatch('John_Michael_Joseph_Smith', 'John*Smith')
True
>>> fnmatch('John_Michael_Joseph_Smith', 'John_Michael*')
True

You could use the filter in a list comprehension to produce a new list of matching dictionaries, testing each dictionary['name'] value against the pattern:

from fnmatch import fnmatch

def namesearch(pattern, dictionaries):
    return [d for d in dictionaries if fnmatch(d['name'], pattern)]

Here namesearch returns a list dictionaries whose 'name' value matches the given pattern:

matched = namesearch('John*Smith', mylist)

Upvotes: 3

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