python学习之路

# print("hello world")

# a=1

#

# print(id(a))

# a=3

# print(id(a))

#

# # 十进制21转化为二进制

# # 21/2=10........1

# #  10/2=5........0

#  #  5/2=2.........1

#  # 2/2=1.........0

#  # 1/2=0.........1

#

# #从下往上10101

#

# #二进制

# 0b101

# #八进制

# 0o101

# #十六进制

# 0x101

# #其他进制转二进制

# print(bin(0x101))

# #其他进制转八进制

# oct(0x100)

# #其他进制转十进制

# int('0o101',8)

# #其他进制转十六进制

# hex(0b10)

# #布尔类型 True False 是int类型

# a=True

# b=False

# print(isinstance(a,int))

#

# #bool 中int类型  0是false  其他都是True

# print(bool(0))

# #%s  占位符

# print("你好 %s 加油%s" %("中国","打工人"))

# d=12

# e=45

# print(d//5)

# print(d%8)

# print(e**6)

# v=[1,2,6]

# b=v[:]

# print(b)

# f="123"

# g="12"

# print(g in f)

# f=456

# g=45

# print(g == f)

#

# a=10

# b=10

# print(a if a>b else b)

# c="123"

# d="1234"

# print("五星红旗"  if c in d else  "我爱中国")

#

# result=0;

# for i in range(101):

#     result+=i

#     i+=1

#

# print(result)

# a=['addd','b','c','d','dd']

# a.append('ff')

# print(a[-1])

# print(a[1:4])

# a={'aa','f',1,5,8,9,4}

# a.add('n')

# for i in range(100000):

#     i+=1;

#     print(a)

# a=[0,5,4,8,9,6,7,9,7]

# print(a.index(9))

# a.insert(3,898)

# print(a)

# del a[4]

# print(a)

# print(a.pop(1))

# b=set(['ad','ff'])

# print(b)

#

# c={1,2,3}

# d={1,2,555}

# print(c.union(d))

# a={8,9,7,6}

# print(a)

#元组 tuple

# top=(1,2,3,[4,5,9])

# print(top)

# top[-1].append(898)

# print(top)

#字典 dict

# a={1:2,4:4}

# a.update({2:89})

# print(a)

# a[1]=56

# print(a)

# print(len(a))

# print(range(899))

# # 要把range变成对象列表需要用list（）函数

#

# print(list(range(89)))

# 地址对象货币代码的值变了，地址变了为不可变对象 ex  int  字符串  元组  ，地址不变为 可变对象

# a={1,2,6}

# print(id(a))

# a.add(56)

# print(id(a))

# a=[0,4,5,6,9,8,7,5,1,2,3,6,4,58,7,8,9,6,45,48,787,87,8787,8,87,87]

# print(a[:])

# print(a[::2])

# print(a[:10:2])

# print(a[5:])

# print(a[0:8])

# [expr for iter_var in iterable]

# [expr for iter_var in iterable if cond_expr]

#[i for  i  in range(101) if i%==0]

# print([i * 8 for i in range(5, 89)])

# print([i for i in range(1, 101) if i % 2 == 0])

# print([[x, y] for x in range(1, 5) for y in range(7)])

# 导包判断是否可以迭代

# from collections.abc import Iterable

# print(isinstance("adcc", Iterable))

# a={'a':1,'v':8,'f':8}

# # print(a.keys())

#拿到的是key

# a={'a':1,'v':8,'f':8}

# for i in  a:

#     print(i)

#求列表里面的的和

# l=[[1,2],[5,8]]

# for [x,y] in l:

#     print('x+y=',x+y)

#生成器返回的是

# c=(i * 2 for i in range(10))

# print(type((i * 2 for i in range(10))))

# print(type([i *2 for i in range(10)]))

# print(next(c))

# print(next(c))#这种超过长度就会报错

#使用循环就不会掉出

# for d in c:

#     print(d)