python语法入门一

• 输出
• 循环分支
• random模块
• 类型
• 运算
• 列表

python下载版本说明 web-based、executable 、 embeddable zipfile
1、X86：对应系統是32位。X86-64对64位系统。
2、web-based、executable 、 embeddable zipfile是什么意思？
web-based: 透过网络安装的，就是执行安装后才透过网络下载python
executable: 可执行文件安装，既把要安装的python全部下载好在本机安装
embeddable zipfile: zip 压缩档，就是python打包成zip压缩包

输出

示例1
示例2

循环分支

print("第一个程序")
temp = input("猜数字:")
guess = int(temp)
while guess != 8:
    if guess == 8:
        print("猜对了")
        print("没奖励")
    else:
        print("猜错了")
    temp = input("猜数字:")
    guess = int(temp)
print("结束")

str = "abcd"
for i in str:
    print(i, end=' ')
# a b c d

strs = ["ab", 'abc', '123']
for i in strs:
    print(i, len(i))
# ab 2
# abc 3
# 123 3

print(range(5))
# range(0, 5)

print(list(range(5)))
# [0, 1, 2, 3, 4]

for i in range(5):
    print(i)
# 0
# 1
# 2
# 3
# 4

for i in range(3, 6):
    print(i)
# 3
# 4
# 5

for i in range(1, 10, 2):
    print(i)
# 1
# 3
# 5
# 7
# 9

x, y = 4, 5
if x < y:
    small = x
else:
    small = y
print(small)
# 4

small = x if x < y else y
print(small)
# 4

random模块

import random

num1 = random.randint(1, 3) # [1, 3]
print(num1)

num2 = random.random() # 随机浮点数 0 <= num2 < 1.0
print(num2)

类型

类型转换
类型判断

运算

列表

arr = ["a", 'bc', '列表']
print(arr)
# ['a', 'bc', '列表']

num = [1, 2, 3, 5]
print(num)
# [1, 2, 3, 5]

mix = [1, 2, 'aa', "bb", [3, 4]]
print(mix)
# [1, 2, 'aa', 'bb', [3, 4]]

num.append(66)
print(len(num))
# 5
print(num)
# [1, 2, 3, 5, 66]

num.extend([333, 444])
print(num)
# [1, 2, 3, 5, 66, 333, 444]

num.insert(1, 'abc')
print(num)
# [1, 'abc', 2, 3, 5, 66, 333, 444]

print(num[0])
# 1

num.remove('abc')
print(num)
# [1, 2, 3, 5, 66, 333, 444]

del num[0]
print(num)
# [2, 3, 5, 66, 333, 444]

num.pop()
print(num)
# [2, 3, 5, 66, 333]
num.pop(1)
print(num)
# [2, 5, 66, 333]

print(num[1:3])
# [5, 66]
print(num[:])
# [2, 5, 66, 333]
print(num[:3])
# [2, 5, 66]
print(num[2:])
# [66, 333]

l1 = [123]
l2 = [321]
print(l1 < l2)
# True
l1 = [123, 321]
l2 = [321, 123]
print(l1 > l2)
# False
print(l1 == l2)
# False
print(l1 + l2)
# [123, 321, 321, 123]

print(123 in l1)
# True
print(123 not in l2)
# False

l1 = [123, 345, 456]
l1 *= 5;
print(l1)
# [123, 345, 456, 123, 345, 456, 123, 345, 456, 123, 345, 456, 123, 345, 456]
print(l1.count(123))
# 5

print(l1.index(345))
# 1
print(l1.index(123, 2, 10))
# 3

l1.reverse()
print(l1)
# [456, 345, 123, 456, 345, 123, 456, 345, 123, 456, 345, 123, 456, 345, 123]

l1 = [2, 3, 7, 6, 0, 3, 5]
l1.sort()
print(l1)
# [0, 2, 3, 3, 5, 6, 7]

l1.sort(reverse=True)
print(l1)
# [7, 6, 5, 3, 3, 2, 0]

l2 = l1[:]
print(l2)
# [7, 6, 5, 3, 3, 2, 0]

l3 = l1
print(l3)
# [7, 6, 5, 3, 3, 2, 0]

l1.sort()
print(l1)
# [0, 2, 3, 3, 5, 6, 7]
print(l2)
# [7, 6, 5, 3, 3, 2, 0]
print(l3)
# [0, 2, 3, 3, 5, 6, 7]