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This tutorial describes the methods that can be used to search a list of dictionaries in Python.

next()Searching a list of dictionaries in Python using the

next()The function can be used to provide the result as the next item in a given iterator. This method also requires the use of fora loop to test the flow against all conditions.

The following code uses next()the function to search a list of dictionaries in Python.

lstdict = [
    {"name": "Klaus", "age": 32},
    {"name": "Elijah", "age": 33},
    {"name": "Kol", "age": 28},
    {"name": "Stefan", "age": 8},
]
print(next(x for x in lstdict if x["name"] == "Klaus"))
print(next(x for x in lstdict if x["name"] == "David"))

Output:

{'name': 'Klaus', 'age': 32}
Traceback (most recent call last):
  File "<string>", line 8, in <module>
StopIteration

The method succeeds when we search for a name that is already present in the dictionary list. However, it gives an error when searching for a name that is not present in the dictionary list StopIteration.

However, this can be easily handled in the code above. You just need to use a slightly different API to adjust and provide default values.

lstdict = [
    {"name": "Klaus", "age": 32},
    {"name": "Elijah", "age": 33},
    {"name": "Kol", "age": 28},
    {"name": "Stefan", "age": 8},
]
print(next((x for x in lstdict if x["name"] == "David"), None))

Output:

None

In addition to looking up the items themselves, we can also look up the index of an item in a list of dictionaries. To achieve this, we can use enumerate()the function.

The following code uses next()the and enumerate()functions to search and find the index of an item.

lstdict = [
    {"name": "Klaus", "age": 32},
    {"name": "Elijah", "age": 33},
    {"name": "Kol", "age": 28},
    {"name": "Stefan", "age": 8},
]
print(next((i for i, x in enumerate(lstdict) if x["name"] == "Kol"), None))

Output:

2

filter()Searching a list of dictionaries in Python using the

filter(function, sequence)function is used to compare sequencewith in Python function. It checks if each element in a sequence is true or not according to a function. By using filter()the function and lambdathe function, we can easily search for an item in a list of dictionaries. In Python 3, filter()the function returns filteran object of the class. We can list()convert this object into a list using the function.

The following code example shows us how to use the filter()and lambdafunctions to search for a specific element in a list of dictionaries.

listOfDicts = [
    {"name": "Tommy", "age": 20},
    {"name": "Markus", "age": 25},
    {"name": "Pamela", "age": 27},
    {"name": "Richard", "age": 22},
]
list(filter(lambda item: item["name"] == "Richard", listOfDicts))

Output:

[{'age': 22, 'name': 'Richard'}]

We use filter()the and functions to search for an element with the key equal to lambdain a list of dictionaries . First, we initialized the list of dictionaries and searched for a value that matched the function using the function . Finally, we converted the result into a list using the function.nameRichardlistOfDictsfilter()lambdalambda item: item['name'] == 'Richard'list()

Searching a list of dictionaries in Python using list comprehensions

List comprehensions are a relatively short and very elegant way to create lists based on given values ​​from existing lists.

We can use list comprehension to return a list that generates the search results for a list of dictionaries in Python.

The following code uses list comprehensions to search a list of dictionaries in Python.

lstdict = [
    {"name": "Klaus", "age": 32},
    {"name": "Elijah", "age": 33},
    {"name": "Kol", "age": 28},
    {"name": "Stefan", "age": 8},
]

print([x for x in lstdict if x["name"] == "Klaus"][0])

Output:

{'name': 'Klaus', 'age': 32}