Python Dictionaries #

<variable> = {'<key1>': '<value1>', '<key2>': '<value2>'}

Values can be anything really.

Select by key #

<variable>['<key>']

get() method #

Return a value from a key based on the specified dictionary

example = {
    "a":"apple",
    "b":"banana"
}

example.get("a")
# "apple"

If the key doesn’t exist, get() returns None.

To specify a different default value:

example.get("a", "Some alternative string")

Assign value #

<variable>['key'] = '<value>'

The update() method can replace or create multiple key-value pairs.

<variable>.update({'<key1>': '<value1>', '<key2>': '<value2>'})

Delete #

del <variable>['<key>']

Or pop(), which deletes and also returns value.

<variable>.pop('<key>')

Check if a key exists #

Returns True or False

'<some key>' in <variable>.keys()

Show the values #

<variable>.values()

Show keys and values #

print(<variable>.items())

Show all:

for key, value in <variable>.items():
  print(key, value)

Update #

Add elements to dictionaries.

dict1.update({"<key>":"value"})

List of dictionaries #

It’s pretty common to have a list full of dictionaries.

Covert list of dictionaries to Pandas dataframe #

import pandas as pd

df = pd.DataFrame(<list_of_dictionaries>)