Python Learning notes--when indexing doesn't work

Dictionary (dict)
phonebook={' cc ': ' 12334 ', ' dd ': ' 123443 '}

>> phonebook (' cc ')
Traceback (most recent call last):
File "<stdin>", line 1, in <mo Dule>
TypeError: ' Dict ' object is not callable
>> phonebook (CC)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
Nameerror:name ' CC ' was not defined
>> s=dict (phonebook)
& gt;> s
{' cc ': ' 12334 ', ' dd ': ' 123443 '}
>> s (cc)
Traceback (most recent call last):
File "<stdin& gt; ", line 1, in <module>
Nameerror:name ' CC ' isn't defined
>> s (' cc ')
Traceback (most recent call Last):
File "<stdin>", line 1, in <module>
TypeError: ' Dict ' object was not callable
>> Phonebo OK
{' cc ': ' 12334 ', ' dd ': ' 123443 '}
>> phonebook (' cc ')
Traceback (most recent call last):
File "< Stdin> ", line 1, in <module>
TypeError: ' Dict ' object was not callable

phonebook[' CC ']
' 12334 '
dict function: Create a dictionary from other mappings or key-value pairs of sequences
items=[(' name ', LX), (' Age ', 26)]
Traceback (most recent):
File "<stdin>", line 1, in <module>
Nameerror:name ' LX ' is not defined

>> items=[(' name ', ' LX '), (' Age ', 26)]
>> c=dict (items)
>> C
{' name ': ' LX ', ' Age ': 26}

D=dict ()

>> D
{}
If no dictionary is defined, an empty dictionary is returned

Dict Basic Operation
Len (d): Returns the number of items contained in D
D[K]: Returns the K value in D
D[K]=V: Assigning value to K in D
Del D[k]: Delete
K in D: query for K keys in D
Elements that are not in dict can also be added by external direct assignment, unlike list needs append

>> d[10]= ' KK '
>> D
{ten: ' KK '}

>> x=[]
>> x[30]= ' KK '
Traceback (most recent):
File "<stdin>", line 1, in <module>
Indexerror:list Assignment index out of range
>> x={}
>> x[30]= ' KK '
>> x
{: ' KK '}
A little piece of practice in the book
people={
' LX ': {
' Phone ': ' 123 ',
' Addr ': ' FDFSF '
},
' Sdy ': {
' Phone ': ' 456 ',
' Addr ': ' Test '
},
' SB ': {
' Phone ': ' 789 ',
' Addr ': ' Test1 '
}

}
labels={' phone ': ' PhoneNumber ',
' Addr ': ' Address '
}
Name=input (' Name: ')
R=input (' Please input number (p) or address (a) ')
If r== ' P ': key= ' phone '
If r== ' a ': key= ' addr '
If name in People:print ("{} ' s {} is {}". Format (Name,labels[key],people[name][key]))
String format feature for Dict:format_map ()
Query keyword corresponding to replace

Dictionary method:
Clear: Clears all items in Dict

>> d={}
>> D
{}
>> d{' name '}= ' LX '
File "<stdin>", line 1
d{' name '}= ' LX '
^
Syntaxerror:invalid syntax
>> d[' name ']= ' LX '
>> D
{' name ': ' LX '}
>> C{}=d.clear ()
File "<stdin>", line 1
C{}=d.clear ()
^
Syntaxerror:invalid syntax
>> C{}.clear ()
File "<stdin>", line 1
C{}.clear ()
^
Syntaxerror:invalid syntax
>> C=d.clear ()
>> C
>> D
{}
Copy: Copying from a dict to B dict
>> x={' name ': ' LX ', ' age ': ' + ', ' height ': ' 170 '}
>> y=x.copy ()
>> y
{' name ': ' LX ', ' age ': ' + ', ' height ': '}### ' #浅复制
The original will not be affected if the value in the replacement copy is taken, and the original value in the in-place modified copy will also be modified
>> x={' name ': ' LX ', ' age ': ' + ', ' height ': [' 170 ', ' 180 ', ' 190 ']}
>> x
{' name ': ' LX ', ' age ': ' + ', ' height ': [' 170 ', ' 180 ', ' 190 ']}
>> y
{' name ': ' xx ', ' age ': ' + ', ' height ': ' 170 '}
>> y=x.copy ()
>> y
{' name ': ' LX ', ' age ': ' + ', ' height ': [' 170 ', ' 180 ', ' 190 ']}
>> y[' height '].remove (' 190 ')
>> y
{' name ': ' LX ', ' age ': ' + ', ' height ': [' 170 ', ' 180 ']}
>> x
{' name ': ' LX ', ' age ': ' + ', ' height ': [' 170 ', ' 180 ']}
>> y[' name ']= ' CC '
>> y
{' Name ': ' CC ', ' age ': ' + ', ' height ': [' 170 ', ' 180 ']}
>> x
{' name ': ' LX ', ' age ': ' + ', ' height ': [' 170 ', ' 180 ']}

Deepcopy: Deep copy, changes in copy do not affect originals

>> from copy import deepcopy
>> d={}
>> D
{}
>> d[' name ']=[' lx ', ' CC '
>> D
{' name ': [' lx ', ' CC ']}
>> c=d.copy ()
>> C
{' name ': [' lx ', ' CC ']}
>> dc=d.deepcopy ()
Traceback (most recent):
File "<stdin>", line 1, in <module>
Attributeerror: ' Dict ' object has no attribute ' deepcopy '
>> Dc=deepcopy (d)
>> d[' name '].append (' DD ')
>> C
{' name ': [' lx ', ' cc ', ' DD ']}
>> DC
{' name ': [' lx ', ' CC ']}
>>

Fromkey: Create a new dict with none

>> Dict.fromkeys ([' Name ', ' age ', ' height '])
{' name ': None, ' age ': none, ' Height ': none}

Get: Provides a relaxed environment

>> c={}
>> print (c[' name ')
Traceback (most recent):
File "<stdin>", line 1, in <module>
Keyerror: ' Name '
>> Print (c.get (' name '))
>> c.get (' name ', N/a)
Traceback (most recent):
File "<stdin>", line 1, in <module>
Nameerror:name ' N ' is not defined
>> c.get (' name ', ' N/A ')
' N/A '

Python Learning notes--when indexing doesn't work