How to Efficiently Search for a Dictionary in a List Based on a Key-Value Pair in Python?

Searching Dictionaries within a List in Python

Problem:

Given a list of dictionaries, how can we efficiently search and retrieve a specific dictionary based on a key-value pair? In this case, we want to find the dictionary with the key "name" set to "Pam."

[
  { "name": "Tom", "age": 10 },
  { "name": "Mark", "age": 5 },
  { "name": "Pam", "age": 7 },
]

Solution:

To perform the search operation, we can leverage Python's built-in generator expressions.

dicts = [
    { "name": "Tom", "age": 10 },
    { "name": "Mark", "age": 5 },
    { "name": "Pam", "age": 7 },
]

result = next(item for item in dicts if item["name"] == "Pam")
print(result)

This code iterates through each dictionary in the list using a generator expression and filters based on the condition "item["name"] == "Pam"". If a matching dictionary is found, the next() function returns the first matching item.

{'name': 'Pam', 'age': 7}

Alternatively, if you need to handle the case where the matching item is not found, you can use the following approach:

next((item for item in dicts if item["name"] == "Pam"), None)

This code returns None if no matching item is found.

To find the index of the matching item rather than the item itself, you can enumerate the list:

next((i for i, item in enumerate(dicts) if item["name"] == "Pam"), None)

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