No.001-Python-学习之路-Day1-编码|注释|变量|交互|流程

charater encoding

 

 

 

First of all

　　computer only know 0 and 1

then sientist use binary to express the number large than one

　　255 --- 1111 1111

then sientist make a correspondence between words and numbers,we call it character encoding

ASCII 255 1bytes
    ---> 1980 gb2312 7000+
      ---> 1995 GBK1.0 2W+
        ---> 2000 GB18030 27000+
       ---> unicode 2bytes
         --->utf-8 en:1bytes zh:3bytes

Coding

Singe Line:

# single line coding by "#"

Multi Lines:

msg = '''
When you want to giveup
tell yourself
"every cloud has a silver lining"
'''
print(msg)

Varable

变量名规则：

　　1.变量名内只能包含字符<英文字符及中文字符>，下划线及数字的组合；

　　2.变量名开头不可以为数字

　　3.变量名不可以是语言关键字，如：and as assert break class continue def del elif # else except finally for from global if import in is lambda not or pass print raise return # try with yield

变量的存储于调用：

# 非盒式存储
list1 = [1, 2, 3] # [1,2,3]开辟内存空间， list1为标签
list2 = list1 # list2为标签2
print(id(list1), id(list2)) # 17223432 17223432
print(list1 is list2) # True

# 可变对象
list3 = [1, 2, 3]
print(id(list3)) # 12994184 于list1对比即使值相同id也不同，不同于不可变对象
list3.append(4)
print(id(list3), list3) # 12994184 [1, 2, 3, 4] id无变化，值变化，修改id不变

def fun(value, default = []): # 加载模块时即生成默认的[]
    default.append(value)
    return default
l1 = fun("a")
l2 = fun("b")
print(id(l1), id(l2), l1, l2) # 23607048 23607048 ['a', 'b'] ['a', 'b'] 值相同，id相同，值异常

# 不可变对象
name1 = "Bruce"
name2 = "Bruce"
print(id(name1), id(name2)) # 16841280 16841280 # 值相同的不可变变量只会创建一个，再次创建只是引用；
print(id(name1.replace("B", "b"))) # 6109248 非在原id上变更，而是直接生成了一片新内存用于存储新值

Interation

username = input("Input your username:")
age = input("Input your age:")
job = input("Input your job:")
salary = input("Input your salay:")

info = '''
--------------info of $----------------
Name:
Age:
Job:
Salary:
'''

# first method --- String splicing ---use multi block memory
info1 = '''
--------------info of ''' + username + '''----------------
Name:''' + username + '''
Age:''' + age + '''
Job:''' + job + '''
Salary:''' + salary + '''
'''
# print(info1)


# second method --- reference variables %s->string %d->integer %f->float
# So default input is string ,we need change str to integer
# [python is strong type definition]
age = int(age)
info2 = '''
--------------info of %s----------------
Name:%s
Age:%d
Job:%s
Salary:%s
''' % (username, username, age, job, salary)
print(info2)


# Third method --- .format() --sometimes you can only use this method
info3 = '''
--------------info of {_name} ----------------
Name:{_name}
Age:{_age}
Job:{_job}
Salary:{_salary}
'''.format(
    _name=username,
    _age=age,
    _job=job,
    _salary=salary)
print(info3)


# Fourth Method ---.format() with {0-N} variables in sequence
info4 = '''
--------------info of {0} ----------------
Name:{1}
Age:{2}
Job:{3}
Salary:{4}
'''.format(username, username, age, job, salary)
print(info4)

 

Python中的流程

程序中的三大流程：

1.自上至下的代码执行------------------顺序

2.根据条件判断执行相应代码---------分支

　　# if....elif....else...

3.根据一定特征循环执行某块代码---循环

　　# while (someting is true) ....

　　# for .... in ......

Loop

for....in......:可以遍历任何序列中的项目，如列表字符串

 

string = "every cloud has a silver lining"
for letter in string:
    print(letter)

# [] is a list
list = ["every", "cloud", "has", "a", "silver", "lining"]
for string in list:
    print(string)

# range() can make a inter list range(begin, end, step)
for string in range(1, 10, 3):
    print(string)

# () is a tuple , if only on parameter tuple is ("parameter",) not ("parameter")
LIST = ("silver1", "lining1")
for string in LIST:
    print(string)

# {} is dict
LIST = {"AA": "BB", "c": "dd"}
# enumerate() can get both index and value of a string,list,dict and tuple .etc
for index, key in enumerate(LIST):
    print("%d-%s:%s" % (index, key, LIST["%s" % key]))

 while (somthing is true):当条件成立是执行循环

 

# "True" mean forever true
# continue mean end cycle of this time
# break mean end the whole loop
count = 0
while True:
    count += 1
    if count % 2 == 0:
        continue
    if count > 100:
        break
    print(count)

# len() can get the num of element in a tuple,list,dict,string
TUPLE = ("every", "cloud", "has", "silver", "lining")
index = 0
while index < len(TUPLE):
    print("index: %d value: %s" % (index, TUPLE[index]))
    index += 1

 

 Judgement

 if.....elif....elif.....else....：按照从上到下顺序，条件成立执行相应程序块并结束judgement，如果条件不成立，则继续向下判断elif，如果都不成立则执行else下面程序块

 

import numpy as np

age = np.random.randint(0, 100, size=1)

chance = 3
times = 0
while chance > 0:
    guess_age = input("你猜的年龄是:")
    if len(guess_age) == 0:
        print("请输入你猜测的年龄")
        continue
    try:
        guess_age = int(guess_age)
        times += 1
        if guess_age == age:
            print("Congratulation!! {times}次猜对".format(times=times))
            break
        elif guess_age < age:
            print("Too Young")
        else:
            print("Too old")
        chance -= 1
        if chance <= 0:
            yes_no = input("3 chance is over!! continue(yes/no):")
            if yes_no == "yes":
                chance += 3
            else:
                print("Bye Bye")
                break
    except ValueError:
        print("你的输入不是0-100间的整数")
        continue

 

 

 

 task-1

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Author   : Bruce Lee

import re


# define a class
class Aaa(object):
    def __init__(self, username, password, data_file):
        self.username = username
        self.password = password
        self.data_file = data_file
        # read file
        self.fp = open(self.data_file, "r")
        self.context = self.fp.readlines()
        self.fp.close()
        # status mark
        self.line = ""
        self.line_list = []
        self.result = 0
        self.index = 0

    def login(self):
        # If not true ,then the result's value is 0
        self.result = 0
        # use For...in.. to get value in list()
        for self.line in self.context:

            self.line_list = re.split(",", self.line.strip())

            if self.username == self.line_list[0]:
                if self.line_list[2] != "1":
                    if self.password == self.line_list[1]:
                        self.result = 1
                        break
                    else:
                        self.result = 3
                        break
                else:
                    self.result = 2
                    break
            else:
                self.result = 4
        return self.result

    def lock(self):
        for self.line in self.context:
            self.index = self.context.index(self.line)
            self.line_list = re.split(",", self.line.strip())

            if self.username == self.line_list[0]:
                self.line_list[2] = "1"
                self.line = ",".join(self.line_list) + "\n"
                self.context[self.index] = self.line

                self.fp = open(self.data_file, "w")
                self.fp.write("".join(self.context) + "\n")
                self.fp.close()

                self.result = 2
                break

        if self.result != 2:
            self.fp = open(self.data_file, "a")
            self.fp.write("%s,NULL,%s%s" % (self.username, "1", "\n"))
            self.fp.close()


# Main program
file = "User_name_and_password.txt"
step = 0
footprint = [["user", 1]]
find_true = 0

while step < 3:
    username1 = input("请输入用户名:")
    if username1 == "":
        print("Please input username!!!")
        continue
    password1 = input("请输入密  码:")

    lg = Aaa(username1, password1, file)
    login_result = lg.login()
    if login_result == 2:
        print("Username has been locked!!!")
        break
    elif login_result == 1:
        print("Welcome to login in my program!!!")
        break
    elif login_result == 4:
        print("Wrong Username!!!!")
        for used_info in footprint:
            if username1 == used_info[0]:
                used_info[1] += 1
                step = used_info[1]
                find_true = 1
                break
        if find_true != 1:
            footprint.append([username1, 1])
            step = 1
        if step < 3:
            continue
        print("Locked")
        lg.lock()
    elif login_result == 3:
        print("Wrong Password!!!!")
        if step < 3:
            continue
        print("Locked")
        lg.lock()

task-2

 

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Author   : Bruce Lee


menu = {
    "吃": {
        "火锅": {
            "海底捞": {11},
            "川锅一号": {11},
            "辣庄重庆老火锅": {22}
        },
        "炒菜": {
            "骆马湖活鱼馆": {},
            "味府": {},
            "项家庄": {}
        },
        "自助": {
          "欢乐牧场": {},
          "金釜山自助烤肉": {},
          "多伦多海鲜自助": {}
        }
    },
    "喝": {
        "矿泉水": {
            "娃哈哈": {},
            "康帅傅": {},
            "百岁山": {}
        },
        "碳酸饮料": {
            "可口可乐": {},
            "雪碧": {},
            "芬达": {}
        },
        "果汁": {
          "农夫果园": {},
          "特种兵": {}
        }
    },
    "玩": {
        "看电影": {
            "万达影城": {},
            "幸福蓝海": {},
            "万象": {}
        },
        "玩游戏": {
            "网咖": {},
            "游戏厅": {},
            "手机": {}
        },
        "游乐园": {
          "夜市": {},
          "千鸟园": {},
          "向阳城": {}
        }
    }
}

current_layer = menu
parent_layers = []

while True:
    for key in current_layer:
        print(key)
    choice = input("你的选择:")
    if choice in current_layer:
        parent_layers.append(current_layer)
        current_layer = current_layer[choice]
    elif choice == "b":
        if parent_layers:
            current_layer = parent_layers.pop()
    elif choice == "q":
        print("谢谢光临，下次再见！")
        break
    else:
        print("无此项")

 

 

 

 

end

参考：

https://www.cnblogs.com/marton/p/10668003.html

https://www.cnblogs.com/wangkun122/p/9082088.html