1) Ternary operation
a,b,c = 2,3,4
d = a if a>b else c
2) base
- binary, 01
- octal, 01234567
- decimal, 0123456789
- Hexadecimal, 0123456789ABCDEF binary to hexadecimal conversion http://jingyan.baidu.com/album/47a29f24292608c0142399cb.html?picindex=1
3) Binary to string decoding, network transmission can only binary encode strings
'&&&20'.encode(encoding = "utf-8")
b'\x82xe2.decode(encoding="utf-8")
4) List operation - in the system it is the memory pointer
names=["Zhang","Li","wang","Yin‘’]
print(names)
print(names[1])
print(names[0:3]) # Take the head but not the tail
print(names[-1]) #Take the first one on the right
print(names[-3:-1]) #same as print(names[-3:])
names.append("Zhu") #Append list
names.insert(1,"insert after Zhang!")
names.pop(1) #delete
print(names.index("Yin")) #Query record position
print(names.count("Yin")) #Count
names.clear() #clear the list "names"
names.reverse() #Reverse
names.sort() #sort
names2 = ["1","2"]
names.extend(names2) #merge names list to names
names3 = names.copy() #copy
names3[2] ="change second Record!"
names4=["Zhang",["Li","wang"],"Yin‘’]
print(names4) #Note the usage of []
names[2] = "xyz"
names2[3][0] = "test"
print(names)
print(names2)
name5 =names #Complete the same, not a simple pointer pointing problem, open a new memory space
print(names)
print(names5)
import copy
names5 = copy.copy(name) #浅copy
names5 = copy.deepcopy(name) #深copy
### Use loop to copy
for i in names:
print(i)
print(name[0:-1:2]) #Step printing is equivalent to print(name[::2]