Dictionarys

Einführung in Python für die Softwareentwicklung

Jasmin Ludolf

Senior Data Science Content Developer

Zutatenliste

ingredients = ["pasta", "tomatoes", "garlic", "basil", "olive oil", "salt"]


# Ingredient quantities (in grams)
quantities = [500, 400, 15, 20, 30, 5]

Dictionary

Dictionary = Schlüssel-Wert-Paare

Ausschnitt aus einem Wörterbuch mit Wörtern (Schlüssel) und ihren Definitionen (Werte)

¹ https://unsplash.com/@sandym10

Zweck von Dictionarys

username
email
preferences

ip_address
location

Rezeptprogramm: Verknüpfung von Zutaten mit Mengenangaben

Symbolhafte Darstellung von Benutzerdaten

Computernetzwerk

¹ Benutzerbild von Bilobaba Vladimir, Aviavlad; https://unsplash.com/@jjying

Dictionary erstellen

# Creating a dictionary
recipe =

Dictionary erstellen

# Creating a dictionary
recipe = {

Dictionary erstellen

# Creating a dictionary
recipe = {"pasta"

Dictionary erstellen

# Creating a dictionary
recipe = {"pasta":

Dictionary erstellen

# Creating a dictionary
recipe = {"pasta": 500

Dictionary erstellen

# Creating a dictionary
recipe = {"pasta": 500,

Dictionary erstellen

# Creating a dictionary
recipe = {"pasta": 500,
          "tomatoes": 400,

Dictionary erstellen

# Creating a dictionary
recipe = {"pasta": 500,
          "tomatoes": 400, 
          "garlic": 15,
          "basil": 20, 
          "olive oil": 30,
          "salt": 5

Dictionary erstellen

# Creating a dictionary
recipe = {"pasta": 500,
          "tomatoes": 400, 
          "garlic": 15,
          "basil": 20, 
          "olive oil": 30,
          "salt": 5}

Wert anhand des Schlüssels abrufen

Elemente im Dictionary sind geordnet
- Abruf von Werten durch Teilmengenbildung anhand der Schlüssel
Wie viel Nudeln brauchen wir?

# Find the ingredient's quantity
print(recipe["pasta"])

Alle Werte abrufen

# Get all values from a dictionary
print(recipe.values())

dict_values([500, 400, 15, 20, 30, 5])

Alle Schlüssel abrufen

# Retrieve all keys in a dictionary
print(recipe.keys())

dict_keys(['pasta', 'tomatoes', 'garlic', 'basil', 'olive oil', 'salt'])

Komplettes Dictionary anzeigen

# Print the dictionary
print(recipe)

{'pasta': 500, 'tomatoes': 400, 'garlic': 15, 'basil': 20, 'olive oil': 30,
'salt': 5}

# Get all items (key-value pairs)
print(recipe.items())

dict_items([('pasta', 500), ('tomatoes', 400), ('garlic', 15), ('basil', 20), 
('olive oil', 30), ('salt', 5)])

Schlüssel-Wert-Paar hinzufügen

# Add a new key-value pair
recipe["parmesan"] = 50

print(recipe)

{'pasta': 500, 'tomatoes': 400, 'garlic': 15, 'basil': 20, 'olive oil': 30,
'salt': 5, 'parmesan': 50}

Wert aktualisieren

print(recipe)

{'pasta': 500, 'tomatoes': 400, 'garlic': 15, 'basil': 20, 'olive oil': 30,
'salt': 5, 'parmesan': 50}

# Updating a value associated with an existing key
recipe["pasta"] = 1000

print(recipe)

{'pasta': 1000, 'tomatoes': 400, 'garlic': 15, 'basil': 20, 'olive oil': 30,
'salt': 5, 'parmesan': 50}

Schlüsselduplikate

# Creating a dictionary with a duplicate key
recipe = {"pasta": 500, "garlic": 5, 
          "garlic": 15, "basil": 20, 
          "olive oil": 30, "salt": 5}


# Print the duplicate key's value
print(recipe["garlic"])

Lass uns üben!

Einführung in Python für die Softwareentwicklung