第一部分:
1.python标准约定文件名:使用小写字母和下划线,如:simple_message.py和simple_messages.py.
2.修改字符串的大小写:
message = "xiejunbo,heLLO woRLD" print(message.title()) print(message.upper()) print(message.lower())
3.合并字符串直接+号连接 .
4.换行符号\n 特殊符号可加转义字符\
5.删除空白:
name = "xiejunbo " print(name.rstrip())
6.在pyhon2中无需将打印内容放在括号内。而python3中的print是一个函数,因此括号必不可少。python2代码有些包含括号,有些不包含。
7.
first_name = "xie" last_name = "junBO" print(first_name + " " + last_name) print(first_name.upper() + " " + last_name.upper()) print(first_name.title() + " " + last_name.title())
8.去空格
first_name = " xie " print("result:" + first_name) print("result:" + first_name.lstrip()) print("result:" + first_name.rstrip()) print("result:" + first_name.strip())
9.转为字符串类型
age = 27 message = "Happy " + str(age) + "rd Birthday!" print(message);
10.注释: 用#号注释
11.使用sort()对数组进行永久排序
12.使用sorted()对数组进行临时排序
13.逆序打印数组reverse()
14.列表长度len(list)
15.
#按顺序生成范围内数字 numbers = range(0,10) for value in numbers: print(value) #list()将range()的结果直接转为列表 _list = list(numbers) print(_list) print(max(numbers))#最大值 print(min(numbers))#最小值 print(sum(numbers))#求和
16.列表解析的写法(实际是for循环缩成一行)
list = [value**2 for value in range(1,9)] print(list) #输出结果:[1, 4, 9, 16, 25, 36, 49, 64]
17.复制列表
users = ['fett','batt','gatt'] vips = users[:] print(users) print(vips) #输出:['fett', 'batt', 'gatt'] ['fett', 'batt', 'gatt']
18.不可变的列表称为元组,需要存储的一组值在整个程序的生命周期内都不变时可使用元组
dimensions = (100,200) print(dimensions) print(dimensions[0]) print(dimensions[1]) #输出:(100, 200) # 100 # 200
19.代码规范:
每级缩进使用4个空格,尽量控制代码行长80以内,注释行长72以内.
20.将一变量的当前值与特定值进行比较
name = "xiejunbo" print(name == "xiejunbo") #output:True
#是否不相等 print(name != "xiejunbo" and name != "zm")
21.检查特定值是否包含在列表
#检查特定值是否不包含在列表中 users = ['fett','batt','gatt','zm'] user = "xiejunbo" user2 = "zm" if user not in users: print("user not in users") elif user2 in users: print("user2 not in users") else: print("in users")
22.
#布尔值 vip = True oVip = False if (vip): print(vip) else: print(oVip)
#判断列表是否为空 tops = [] if tops:print(tops) else:print("list is null")
23.字典操作
#字典,实际上跟java的map一样,存储一系列键值对 #创建字典 alien = {} alien["first_name"] = "xie" alien["last_name"] = "junbo" alien["job"] = "developer" print(alien) #output: {'last_name': 'junbo', 'job': 'developer', 'first_name': 'xie'} #修改字典值 alien["job"] = "programmer" print(alien) #output:{'last_name': 'junbo', 'job': 'programmer', 'first_name': 'xie'} #删除字典 del alien["job"] print(alien) #output:{'last_name': 'junbo', 'first_name': 'xie'} #遍历字典键值对 for key, value in alien.items(): print("key:" + key) print("value:" + value) #output:key:last_name # value:junbo # key:first_name # value:xie #遍历字典中所有键, 所有值用values() for key in alien.keys(): print(key.title()) #output: Last_Name # First_Name #按顺序遍历字典中所有键,实际先排序再遍历 for key in sorted(alien.keys()): print(key.title())
24.用户输入
#input()等待用户输入并输出内容 message = input("Please input someth and I will return it to you:") print(message) #int() 获取数值输入 age = input("How old are you?") age = int(age) print(age) #Please input someth and I will return it to you:18 #18 #How old are you?
25.用户输入填充字典
responses = {} #设置一个标识位,指出调查是否继续 polling_active = True while polling_active : #提示输入被调查者的名字和回答内容 name = input("What's your name?") response = input("Which mountain would you like to climb someday?") #将答卷存在字典中 responses[name] = response #看是否还有人要参与调查 repeat = input("Would like to let another person respond? (yes/no)") if repeat == 'no': polling_active = False #调查结束,显示结果 print("\n---poll result---") for name, response in responses.items(): print(name + "would like to climb " + response + ".") #What's your name?xiejunbo #Which mountain would you like to climb someday?Baiyun mountain #Would like to let another person respond? (yes/no)yes #What's your name?zm #Which mountain would you like to climb someday?Fengyun mountain #Would like to let another person respond? (yes/no)no #---poll result--- #xiejunbowould like to climb Baiyun mountain. #zmwould like to climb Fengyun mountain.
26.函数
#指定形参默认值的函数 def greet_user(name = "zm"): """Warnly welcome""" print("函数内部打印:热烈欢迎" + name) return name print("外部打印:" + greet_user("xiejunbo")) print("内部打印:" + greet_user()) #output: #函数内部打印:热烈欢迎xiejunbo #外部打印:xiejunbo #函数内部打印:热烈欢迎zm #内部打印:zm