Found 10805 Articles for Python

Dicts are hash tables. No tree searching is used. Looking up a key is a nearly constant time(Amortized constant) operation, regardless of the size of the dict. It creates the hash of the key, then proceeds to find the location associated with the hashed value. If a collision listed address is encountered, it starts the collision resolution algorithm to find the actual value.This causes dictionaries to take up more space as they are sparse.

You can get all the values using a call to dict.values(). Then you can call ", ".join on the values to concatenate just the values in the dict separated by commas. examplea = {'foo': "Hello", 'bar': "World"} vals = a.values() concat = ", ".join(vals) print(concat)OutputThis will give the output −Hello, World

Dicts are hash tables. No tree searching is used. Looking up a key is a nearly constant time(Amortized constant) operation, regardless of the size of the dict. It creates the hash of the key, then proceeds to find the location associated with the hashed value. If a collision listed address is encountered, it starts the collision resolution algorithm to find the actual value.This causes dictionaries to take up more space as they are sparse.

The easiest way to convert a spreadsheet to Python dictionary is to use an external library like pandas. This provides very helpful features like to_dict on excel objects. You can use these like −Examplefrom pandas import * xls = ExcelFile('my_file.xls') data = xls.parse(xls.sheet_names[0]) print(data.to_dict())OutputThis will give the output −{'id': 10, 'name': "John"}

The JSON module is a very reliable library to serialize a Python dictionary into a string, and then back to a dictionary. The dumps function converts the dict to a string. exampleimport json my_dict = {    'foo': 42,    'bar': {       'baz': "Hello",       'poo': 124.2    } } my_json = json.dumps(my_dict) print(my_json)OutputThis will give the output −'{"foo": 42, "bar": {"baz": "Hello", "poo": 124.2}}'The loads function converts the string back to a dict. exampleimport json my_str = '{"foo": 42, "bar": {"baz": "Hello", "poo": 124.2}}' my_dict = json.loads(my_str) print(my_dict['bar']['baz'])OutputThis will give the output −Hello

You can use any hashable object like int, string, etc as a key in a python dict. You need to separate it from the value using the ':' delimiter. The value can be any type of object. Consecutive key value pairs must be separated by a comma.

It is pretty easy to get the sum of values of a Python dictionary. You can first get the values in a list using the dict.values(). Then you can call the sum method to get the sum of these values. exampled = {    'foo': 10,    'bar': 20,    'baz': 30 } print(sum(d.values()))OutputThis will give the output −60

You can convert Python dictionary keys/values to lowercase by simply iterating over them and creating a new dict from the keys and values. For example, def lower_dict(d):    new_dict = dict((k.lower(), v.lower()) for k, v in d.items())    return new_dict a = {'Foo': "Hello", 'Bar': "World"} print(lower_dict(a))This will give the output{'foo': 'hello', 'bar': 'world'}If you want just the keys to be lower cased, you can call lower on just that. For example, def lower_dict(d):    new_dict = dict((k.lower(), v) for k, v in d.items())    return new_dict a = {'Foo': "Hello", 'Bar': "World"} print(lower_dict(a))This will give the output{'foo': 'Hello', 'bar': ... Read More

Python and javascript both have different representations for a dictionary. So you need an intermediate representation in order to pass data between them. The most commonly used intermediate representation is JSON, which is a simple lightweight data-interchange format.ExampleThe dumps function converts the dict to a string. For example, import json my_dict = {    'foo': 42,    'bar': {       'baz': "Hello",       'poo': 124.2    } } my_json = json.dumps(my_dict) print(my_json)OutputThis will give the output:'{"foo": 42, "bar": {"baz": "Hello", "poo": 124.2}}'ExampleThe load's function converts the string back to a dict. For example, import json my_str ... Read More

A python dictionary is a Hashmap. You can use the map data structure in C++ to mimic the behavior of a python dict. You can use map in C++ as follows:#include #include using namespace std; int main(void) {    /* Initializer_list constructor */    map m1 = {       {'a', 1},       {'b', 2},       {'c', 3},       {'d', 4},       {'e', 5}    };    cout