python--Dictionary

Also known as a hash table

Common dictionary built-in methods

Dict.clear ()

Dict.fromkeys ()

# Create a new dictionary with the key of the dictionary in sequence seq, Val for the dictionary all keys corresponding to the initial value >>> list =[1,2,3]>>> dict =  Dict.fromkeys (list)>>> dict{1:none, 2:none, 3: None}>>> dict = Dict.fromkeys (list,1)>>> dict{1:1, 2:1, 3:1}

Dict.get (Key, Default=none)    # Returns the value of the specified key if the value does not return the default value in the dictionary

Dict.has_key (key)    # returns False if the key returns true in the dictionary dict

Dict.items ()    # Returns an array of traversed (key, value) tuples in a list

Dict.keys ()    # Returns a dictionary of all keys in a list

Dict.values ()    # returns all values in the dictionary as a list

Dict.setdefault (Key, Default=none)    # is similar to get (), but if the key does not already exist in the dictionary, the key will be added and the value will be set to default

Dict.update ()

# update the key/value pairs of the dictionary dict2 to dict >>> Dict1 = {1:'a'}>>> dict2 = { 2:'b'}>>> dict1.update (dict2)>>> dict1{  'a'b'}

python--Dictionary