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  2. Dictionary Methods in Python | Install 2 (update (), has_key (), fromkeys () …)

Dictionary Methods in Python | Install 2 (update (), has_key (), fromkeys () …)



# Python code to demonstrate how it works
# fromkeys () and update ()

 
# Initializing dictionary 1

dic1 = { ` Name` : `Nandini` , `Age` : 19 }

 
# Initializing Dictionary 2

dic2 = { `ID` : 2541997 }

 
# Initializing sequence

sequ = ( ` Name` , `Age` , `ID` )

  
# using update to add dic2 values ​​to dic 1
dic1.update (dic2)

 
# print updated dictionary values ​​

print ( "The updated dictionary is:" )

print ( str (dic1))

 
# using fromkeys () to convert sequence to dictionary

dict = dict . fromkeys (sequ, 5 )

 
# print new dictionary values ​​

print ( "The new dictionary values ​​are:" )

print ( str ( dict ))  

Output: 

 The updated dictionary is: {`Age`: 19 , `Name`:` Nandini`, `ID`: 2541997} The new dictionary values ​​are: {` Age`: 5, `Name`: 5,` ID`: 5}

3. has_key () : — This function returns true if the specified dictionary is in the dictionary, otherwise it returns false.

4. get (key, def_val) : — This function returns the key value associated with the key mentioned in the arguments. If the key is missing, the default is returned.

# Python code to demonstrate how it works
# has_key () and get ()

 
# Dictionary initialization

dict = { `Name` : ` Nandini` , `Age` : 19 }

  
# using has_key () to check if there is dic1 has a key

if dict . has_key (  `Name` ):

  print ( "Name is a key" )

else : print ( "Name is not a key" )

 
# using get () to print the key value

print ( "The value associated with ID is:" )

print ( dict . get ( `ID` , "Not Present" ))

 
# print dictionary values ​​

print ( "The dictionary values ​​are:" )

print ( str ( dict ))

Output: 

 Name is a key The value associated with ID is: Not Present The dictionary values ​​are: {`Name`:` Nandini`, `Age`: 19}

5. setdefault (key, def_value) : — This function also looks for a key and displays its value like get (), but creates a new key with def_value if the key is missing.

# Python code to demonstrate how it works
# set as default ()

 
# Initializing the dictionary

dict = { `Name` : `Nandini` , ` Age` : 19 }

 
# using setdefault () to print the key value

print ( "The value associated with Age is:" , end = "")

print ( dict . setdefault ( `ID` , " No ID " ))

  
# print dictionary values ​​

print ( "The dictionary values ​​are:" )

print ( str ( dict ))

Output: 

 The value associated with Age is: No ID The dictionary values ​​are: {`Name`:` Nandini`, `Age`: 19,` ID` : `No ID`}

This article is courtesy of Manjeet Singh . If you are as Python.Engineering and would like to contribute, you can also write an article using contribute.python.engineering or by posting an article contribute @ python.engineering. See my article appearing on the Python.Engineering homepage and help other geeks.

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