Dictionary of normal operation

Disclaimer: # dictionary is a variable type: where the key immutable, value variable format key: value

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1 priority master
1, in accordance with the key: value mapping relationship value (can be kept desirable)
2, members of the operation in, not in # the default judgment Key
3, len () # Get the current key-value pairs in a dictionary the number of
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1. # dictionary definition of three ways

= {D1 ' name ' : ' Egon ' , ' Age ' : 2 }
 Print (D1)
 # The second embodiment: dict () 
D1 = dict (name = ' Sean ' , Age =. 1 )
 Print (type (D1) )
 # third way: zip Learn 
L1 = [ ' name ' , ' Egon ' ]
l2 = ['age',2]
z1 = zip(l1,l2)
print(z1)
print(dict(z1))

2. Dictionary additions and deletions take

d1 = {'name':'egon','age':2,'hopy':'ee'}

# Operation by 
D1 [ '' weight] = 178 
# puncturing operation with a list Remove 
del completely remove 
d1.clear () to clear the data dictionary

# D1.pop () pop ( 'key ') to delete the specified key, the return value is the key value 
# d1.popitem () Returns the value of the random delete the key is a tuple

# Fetch operation 
D1 = { ' name ' : ' Egon ' , ' Age ' : 2, ' HopY ' : ' EE ' }
 Print (D1 [ ' name ' ]) 
# d1.get ()

print(d1.get('name','age')

# Change operation 
D1 [ ' Age ' ] = 73 is
 Print (D1)

Change #update present new cover absence 
d1.update ({ 'name': 'Nezha'}) 
Print (D1) 
d1.update ({ 'Sex': 'MALE'}) 
Print (D1)

# Setdefault: Note the difference between the update key does not exist new key-value pairs, return the new value, key corresponding to the presence of return value 
Print (d1.setdefault ( 'Sex', 'FEMALE'))

# in  not in

print('name' in d1)

Keys #, values, items ****** 
Print (d1.keys ()) # returns all Key 
Print (of the type (d1.keys ())) # type 'dict_keys' 
Print (d1.values ()) # return all value 
Print (d1.items ()) returns all of the # key-value pairs, set the return value is a list of tuples, each key tuple pair present in

for key in d1.keys():
    print(key)
for value in d1.values():
    print(value)
for key,value in d1.items():
    print(key,value)

# Fromkeys: the production of a new dictionary, the first parameter (list), it will first argument of each element of key, the second parameter value to form a new dictionary 
print (dict.fromkeys ([1, 2,3], [ 'k1', 'k2']))