It's been such a long time before I wrote Primer 2, I'm really embarrassed.
- list, tuple
First of all, lists and tuples are ordered, and tuples can be understood as read-only lists (const), using '[' for lists and '(' for tuples.
#! /usr/bin/env python
# Author: JackyHou
names = ["zhangsan", "lisi", "wangwu"]
names.append("lijingyi")#Add after
names.insert(1, "xiaolizi")
# print(names[0:2])#Left closed and right open
#
# print(names[-1])#Start counting from the right
# print(names[-3:])#Do not write anything after the colon, that is, the third from the right until the last
# print(names[:3])
print(names)
#delete
#method 1
# names.remove("xiaolizi")
# print(names)
#Method 2
# del names[1]
# print(names)
#method 3
# names.pop()# can take parameters
# print(names)
#find
print(names.index("xiaolizi"))
print(names.pop(names.index("xiaolizi")))
print(names)
#count
names.append("lijingyi")
print(names.count("lijingyi"))
#reverse
names.reverse()
print(names)
#sort
names.sort()
print(names)
#extend
names2 = [1, 2, 4, 5]
names.extend(names2)
of the names2
print(names)
One thing to pay attention to when using lists: the problem of shallow and deep copies
Shallow copy: copy
Deep copy: deepcopy
The difference between them is that when the list is a multi-level list, shallow copying and direct assignment will make the pointers of the secondary lists of the two objects point to the same object (that is, any operation will be reflected on the two objects, and both objects will be lost. One is prosperous), and deep copy is usually understood copy (full copy)
#! /usr/bin/env python # -*- coding:utf-8 -*- # Author: JackyHou import copy person = ['name', ['saving', 100]] # p1 = copy.copy(person) # p2 = person[:] # p3 = list(person) p1 = person[:] p2 = person[:] p1 [0] = 'hjq' p2 [0] = 'ljy' p1[1][1] = 50 print(p1) print(p2)
[1, ['equal', 2, 4], 4] [1, ['equal', 2, 4], 4] [1, ['equal', 'copy', 4], 4] [1, ['equal', 'copy', 4], 4] [1, ['equal', 'copy', 4], 4] [1, ['equal', 'copy', 'deepcopy'], 4]
- Basic operations on String
#! /usr/bin/env python
# Author: JackyHou
name = "my name is {name}, I'm {year}."
print(name.capitalize())
print(name.count('a'))
print(name.center(50, '*'))
print(name.endswith("ou"))
print(name.expandtabs(30))
print(name.find('is'))
print(name.format(name='JackyHou', year=22))
print(name.format_map({'name': 'JackyHou', 'year': 22}))
print(name.isalnum())
print('abc123'.isalnum())
print('abcABC'.isalpha())
print('1A'.isdecimal())
print('_1a'.isidentifier())#Determine whether it is a valid identifier
print('abc'.islower())#Is it lowercase?
print('22.11'.isnumeric())#Pure numbers
print(name.isspace())
print('My Name Is'.istitle())
print('My Name is'.isprintable())#tty file, drive file
print("My Name is".isupper())
print(':'.join(['1', '2', '3']))
print (name.ljust (50, '*'))
print(name.rjust(50, '*'))
print("Jacky".lower())
print("Jacky".upper())
print(' \nhaha'.lstrip())
print('haha \n'.rstrip())
print ('hha' .strip ())
la = str.maketrans("abcdef", '123456')
print("JackyHou".translate(la))
print(name.replace('m', '1', 2))
print('hahahxhahahxha'.rfind('x'))#Start to find from the right
print ('hah hah haha ah'.split ('')) #split
print ('hahah + dkfjal \ njldafjlad'.splitlines ()) #Split line
print('JackyHou'.swapcase())#Reverse case
print('hah hah ha'.title())
print('jacky hou'.zfill(50))
- dictionary
#! /usr/bin/env python
# Author: JackyHou
#key-value
info = {
'stu1101': "TengLan Wu",
'stu1102': "LongZe Luola",
'stu1103': "XiaoZe Maliya",
}
print(info)
#print(info["stu1101"])
info["stu1101"] = "武藤兰"
info["stu1104"] = "CangJingkong"
print(info)
#del info["stu1101"]
# info.pop("stu1101")
# info.popitem()# Delete one randomly
# print(info)
#find
print(info.get('stu1105'))
print('stu1105' in info)
b = {
'stu1101': "Rihana",
1: 3,
4: 5,
}
info.update(b)
print(info)
c = dict.fromkeys([6, 7, 8], [1, {"name": "alex"}, 444])
print(c)
c[7][1]['name'] = "Jack Chen"#This is a pit!!!!!!!!!!!! The fromkeys function will treat the latter as a whole, so if you change one, it will be all changed
print(c)
print(info.items())
#efficient
for i in info:
print(i, info[i])
#inefficient
for k, v in info.items():
print (k, v)
- tertiary menu
#! /usr/bin/env python
# Author: JackyHou
# data = {
# 'Beijing': {
# "沙河": ["oldboy", "test"],
# "Tiantongyuan": ["Lianjia Real Estate", "I love my home"]
# },
# "Chaoyang": {
# "Wangjing": ["Benz", "Momo"],
# "国贸": ["CICC", "HP"],
# "Dongzhimen": ["Advent", "Fetion"],
# },
#
# }
data = {
'Beijing': {
'Haidian': {
'Wudaokou': {
'soho': {},
'NetEase': {},
'google': {}
},
'Zhongguancun': {
'IQIYI': {},
'Autohome': {},
'youku': {},
},
'Uechi': {
'Baidu': {},
},
},
'Changping': {
'Shahe': {
'old boys': {},
'Beihang': {},
},
'Tiantongyuan': {},
'Huilongguan': {},
},
'Chaoyang': {},
'Dongcheng': {},
},
'Shanghai': {
'Minhang': {
"People's Square": {
'Fried Chicken': {}
}
},
'Zhabei': {
'train battle': {
'Ctrip': {}
}
},
'Pudong': {},
},
'Shandong': {},
}
exit_flag = False
while not exit_flag:
#first level menu
for i in data:
print(i)
choice = input("SELECT>>>>>:")
if choice in data:
while not exit_flag:
#Second level menu
for j in data[choice]:
print("\t", j)
choice2 = input("SELECT>>>>>:")
if choice2 in data[choice]:
while not exit_flag:
#third level menu
for k in data[choice][choice2]:
print("\t\t", k)
choice3 = input("SELECT>>>>>:")
if choice3 in data[choice][choice2]:
for n in data[choice][choice2][choice3]:
print("\t\t\t", n)
choice4 = input("INPUT 'b' TO BACK")
if choice4 == 'b':
pass
elif choice4 == 'q':
exit_flag = True
if choice3 == "b":
break
elif choice3 == 'q':
exit_flag = True
if choice2 == 'b':
break
elif choice2 == 'q':
exit_flag = True
if choice == 'b':
break
elif choice == 'q':
exit_flag = True
Pay attention to the usage of pass:
It's not really useful. pass is the empty statement, in order to maintain the integrity of the program structure. do nothing,
Half are used as placeholder statements.
Half are used as placeholder statements.