Example 1: python dictionary get default
dictionary = {"message": "Hello, World!"}
data = dictionary.get("message", "")
print(data) # Hello, World!
Example 2: how to get the key for a value in a dictionary in python
# function to return key for any value
def get_key(val):
for key, value in my_dict.items():
if val == value:
return key
return "key doesn't exist"
# Driver Code
my_dict ={"java":100, "python":112, "c":11}
print(get_key(100))
print(get_key(11))
Example 3: how to get the value of key in python
print(dict["key"])
Example 4: python dictionary access value by key
# Create a list of dictionary
datadict = [{'Name': 'John', 'Age': 38, 'City': 'Boston'},
{'Name': 'Sara', 'Age': 47, 'City': 'Charlotte'},
{'Name': 'Peter', 'Age': 63, 'City': 'London'},
{'Name': 'Cecilia', 'Age': 28, 'City': 'Memphis'}]
# Build a function to access to list of dictionary
def getDictVal(listofdic, name, retrieve):
for item in listofdic:
if item.get('Name')==name:
return item.get(retrieve)
# Use the 'getDictVal' to read the data item
getDictVal(datadict, 'Sara', 'City') # Return 'Charlotte'
# -------------------
# to convert a dataframe to data dictionary
df = pd.DataFrame({'Name': ['John', 'Sara','Peter','Cecilia'],
'Age': [38, 47,63,28],
'City':['Boston', 'Charlotte','London','Memphis']})
datadict = df.to_dict('records')
Example 5: how to get value from key dict in python
# Get a value from a dictionary in python from a key
# Create dictionary
dictionary = {1:"Bob", 2:"Alice", 3:"Jack"}
# Retrieve value from key 2
entry = dictionary[2]
# >>> entry
# Alice