python get key from value

# 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])

dict = {'color': 'blue', 'shape': 'square', 'perimeter':20}
dict.get('shape') #returns square

#You can also set a return value in case key doesn't exist (default is None)
dict.get('volume', 'The key was not found') #returns 'The key was not found'

# 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)) 

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)]) 

# 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