access python dictionary values code example

Example 1: dictionaries in python 3

clear() - Removes all the elements from the dictionary
copy() - Returns a copy of the dictionary
fromkeys() - Returns a dictionary with the specified keys and value
get() - Returns the value of the specified key
items() - Returns a list containing a tuple for each key value pair
keys() - Returns a list containing the dictionary's keys
pop() - Removes the element with the specified key
popitem() - Removes the last inserted key-value pair
setdefault() - Returns the value of the specified key. If the key does not exist: insert the key, with the specified value
update() - Updates the dictionary with the specified key-value pairs
values() - Returns a list of all the values in the dictionary

Example 2: 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')