Python:dict Study Notes

Dict full name dictionary, using key-value (key-value) storage, there is a very fast search speed.

Here are some common dict usage

Defined

>>> dict={}>>> dict={'Adele':'Hello','Taylor':'1989'}>>>dict{'Taylor':'1989','Adele':'Hello'}

Nesting

>>> A_dict={1:"{one: ' A ', ': ' B '}", 2:"2B", 3:"3C"}>>>a_dict{1:"{one: ' A ', ': ' B '}", 2:'2B', 3:'3C'}>>> a_dict[1][12]'b'

Gets the key, value

>>>A_dict.keys () [1, 2, 3]#The result is a list>>>a_dict.values () ["{one: ' A ', ': ' B '}",'2B','3C']>>>A_dict.items () [(1,"{one: ' A ', ': ' B '}"), (2,'2B'), (3,'3C')]#The result is that the elements inside the list,list are tuples>>> forKeyincha_dict: ...Print(key) ...123>>> forValueincha_dict.values (): ...Print(value) ... {11:'a', 12:'b'}2b3c>>> forKeyincha_dict: ...PrintA_dict[key] ... {11:'a', 12:'b'}2b3c>>> forKvinchA_dict.items (): ...PrintSTR (k) +":"+Str (v) ...1:{11:'a', 12:'b'}2: 2B3: 3C>>> forKincha_dict: ...PrintSTR (k) +":"+str (a_dict[k]) ...1:{11:'a', 12:'b'}2: 2B3: 3C>>> forKincha_dict: ...Print "a_dict (%s) ="%K,a_dict[k] ... a_dict (1) = {11:'a', 12:'b'}a_dict (2) =2ba_dict (3) =3C>>> A_dict.get (1)"{one: ' A ', ': ' B '}"

Delete

>>> A_dict.pop ('Taylor')'1989'  #Delete based on key value, and return value>>>delA_dict[1]>>>a_dict{2:'2B', 3:'3C','Adele':'Hello'}>>>a_dict.clear ()>>>a_dict{}

Copy

>>> new_dict=a_dict.copy ()>>> new_dict{"{one: ' A ', ' B '} " ' 2B ' ' 3C '}

Merge

>>> add_dict={'Adele':'Hello','Taylor':'1989'}>>>a_dict.update (add_dict)>>>a_dict{1:"{one: ' A ', ': ' B '}", 2:'2B', 3:'3C','Adele':'Hello','Taylor':'1989'}

Sort

>>>PrintSorted (A_dict.items (), key=LambdaD:d[0]) [(1,"{one: ' A ', ': ' B '}"), (2,'2B'), (3,'3C')]#Sort by Key>>>PrintSorted (A_dict.items (), key=LambdaD:d[1])[(2,'2B'), (3,'3C'), (1,"{one: ' A ', ': ' B '}")]#Sort by Value

Subsequent use, add:

Python:dict Learning Notes