1.编写第一个程序,目前使用的都是python 3
# print('hello world!')
2.查看当前python编辑器的版本号
# python -v
3.使用变量
# message = 'hello world!' # print(message)
4.字符串
name = 'jetty' print(name.title()) #Jetty 首字母大写 print(name) # jetty name.upper() #JEETY 转大写 name.lower() #jetty 转小写
5.合并拼接字符串
first_name = 'hongzhu' last_name = 'zhan' full_name = last_name +" "+ first_name print(full_name) # zhan hongzhu
6.使用制表来添加空白
language = 'python\nJavascript\nC\nRust' print(language) # 打印 python Javascript C Rust
7.删除空白
_blank = ' python ' print(_blank.rstrip()) #去除右侧空白 print(_blank.strip()) #去除两侧空白 print(_blank.lstrip()) #去除左侧空白
8.变量类型
num = 2.340 print(int(num)) # 整型 2 print(float(num)) # 浮点型 2.34
9.列表
color = ['red','green','yellow','pink'] # 访问元素 print(color[0]) #red # 修改 color[0] = 'black' # 添加元素 color.append('orange') # 插入元素 color.insert(0,'blue') 插到第一位 print(color) # 删除元素 del color[0] #删除当前元素 color.pop() # 删除数组最后一个元素 color.remove('red') # 删除红色
10 组织列表
排序列表
num_list = [1,2,3,4,2,1,3,1,2] num_list.sort() print(num_list) #[1, 1, 1, 2, 2, 2, 3, 3, 4]
临时排序
num_list = [1,2,3,4,2,1,3,1,2] print(sorted(num_list)) #[1, 1, 1, 2, 2, 2, 3, 3, 4]
reverse 反序
num_list = [1,2,3,4,2,1,3,1,2] num_list.reverse() print(num_list) #[2, 1, 3, 1, 2, 4, 3, 2, 1]
列表的长度
num_list = [1,2,3,4,2,1,3,1,2] print(len(num_list)) # 9
11 遍历列表
num_list = [1,2,3,4,2,1,3,1,2] for i in num_list: print(i,end=" ") # 一行显示
12.使用函数遍历
num_list = [1,2,3,4,2,1,3,1,2] for i in range(len(num_list)): print(num_list[i],end=" ")
13.乘方运算
squares = [] for i in range(1,6): squares.append(i**2) print(squares) #[1, 4, 9, 16, 25]
14.内置函数
num_list = [1,2,3,4,2,1,3,1,2] print(max(num_list)) #4 print(min(num_list)) #1 print(sum(num_list)) #19
15.列表解析
squeres = [value**2 for value in range(1,11)] print(squeres) #[1, 4, 9, 16, 25, 36, 49, 64, 81, 100]
16.练习示例
16.1 1-50奇数的和
odd_number =[] for i in range(1,11,2): odd_number.append(i) print(sum(odd_number))
16.2 3-90 3的倍数
three_nmu = [] for i in range(3, 91): if (i % 3==0): three_nmu.append(i) print(three_nmu)
16.3 1-10 的立方
squares = [] for i in range(3,11): squares.append(i**3) print(squares)
16.4 1-10 的立方列表解析
squares = [i**3 for i in range(3,11)] print(squares)
17 列表切片
num_list = [1,2,3,4,2,1,3,1,2] print(num_list[0:5]) #[1, 2, 3, 4, 2] 从第一个开始取值到第五位 print(num_list[:5]) #[1, 2, 3, 4, 2] 默认会从第一个开始取值 print(num_list[5:]) #[1, 3, 1, 2] 取后面的4位
18 元组
dimensions = (100,300) print(dimensions[0]) #100 for i in dimensions: print(i) #100 300
19 if 语句
num_list = [1, 2, 3, 4, 2, 1, 3, 1, 2] for i in num_list: if i == 2: print(i)
20 !=
num_list = [1, 2, 3, 4, 2, 1, 3, 1, 2] for i in num_list: if i != 2: print(i)
21 and
num_list = [1, 2, 3, 4, 2, 1, 3, 1, 2] for i in num_list: if i >=1 and i <=2: print(i)
22 字典
alien = {'color':0,'points':1} print(alien['color']) #color
23 修改字典
alien = {'color':0,'points':1} alien['color'] = 'red' print(alien) #{'color': 'red', 'points': 1}
24 删除字典
alien = {'color':0,'points':1} del alien['color'] print(alien)
