dictionary:
1, the basic feature dictionary
dict is represented by {} key data: unique {key value}
Hash keys must be immutable data types can be used as a dictionary key
Value without any restrictions
2, CRUD
increase:
dic[key] = value
dic.setdefault (key, value) # If the key exists in the dictionary do nothing, or to add
# Can be queried by a key, this key does not return None
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delete:
pop (key) # returns a value returned is the value to be deleted
del dic[key]
clear () # Empty dictionary
popitem () # random deleted
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change:
dic[key] = value
dic.update (dictionary)
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check:
dic.get(key)
dic[key]
for loop
setdefault(key)
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3, other operations dictionary
dic.keys acquired all [key] is present in a high copy list
dic.values all acquired values [] a list of the presence of a high copy
dic.items acquired all of the [key] to [] tuples present in the form of a list of a high imitation
Deconstruction:
a,b = 1,2
a,b = (1,2)
a,b = [1,2]
a,b = "12"
4, nested dictionary
DIC = {
"name": "Feng Wang",
"Age": 43 is,
"wife": {
"name": "Zhang",
"Age": 39,
"the salary": 100000,
},
"Baby": [
{ "name": "boss", "Age": 18 is},
{ "name": "second child", "Age": 15}
],
}
DIC [ "Baby"] [0] [ "Age"] =. 19 # step by step to find and change the corresponding [value]
print (dic)