how to get the key for a value in a dictionary in python

# To get all the keys of a dictionary use 'keys()'
newdict = {1:0, 2:0, 3:0}
newdict.keys()
# Output:
# dict_keys([1, 2, 3])

# 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)) 

# Python program to show working  
# of keys in Dictionary 
  
# Dictionary with three keys 
Dictionary1 = {'A': 'Geeks', 'B': 'For', 'C': 'Geeks'} 
  
# Printing keys of dictionary 
print(Dictionary1.keys()) 
  
# Creating empty Dictionary 
empty_Dict1 = {} 
  
# Printing keys of Empty Dictionary 
print(empty_Dict1.keys()) 

print(dict.get("key"))

print(dict["key"])

# creating a new dictionary 
my_dict ={"java":100, "python":112, "c":11} 
  
# list out keys and values separately 
key_list = list(my_dict.keys()) 
val_list = list(my_dict.values()) 
  
print(key_list[val_list.index(100)]) 
print(key_list[val_list.index(112)]) 
  
# one-liner 
print(list(my_dict.keys())[list(my_dict.values()).index(112)]) 

d = {2:"hello"}
d.values()

## Values need to be unique

# creating a new dictionary 
my_dict ={"java":100, "python":112, "c":11} 
  
# list out keys and values separately 
key_list = list(my_dict.keys()) 
val_list = list(my_dict.values()) 
  
print(key_list[val_list.index(100)]) 
print(key_list[val_list.index(112)]) 
  
# one-liner 
print(list(my_dict.keys())[list(my_dict.values()).index(112)]) 

# 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')

# 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