how to find key by value in dictionary python code example
Example 1: 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 2: find key by value python
print(list(d.keys())[list(d.values()).index(990)])