目录
一、前言
一些文章参考
https://www.zhihu.com/question/348263788
python官网
python入门指南
二、基础知识笔记
1、python基础、函数
def basicStr():
print('I\'m ok.')
print('I\'m learning\nPython.')
print('\\\n\\') #\\就是\ \n换行
print('\\\t\\') #\t为制表符
print('''line1
... line2
... line3''')
print('''line1
line2
line3''')
print(r'''hello,\n
world''') #r''不转义
print(True or False)
print(True and False)
print(not 1 > 2)
print(10 / 3) #浮点数
print(10 // 3) #除数
print(10 % 3) #余数
print('Hello, %s' % 'world')
print('Hi, %s, you have $%d.' % ('Michael', 1000000))
print('%2d-%02d' % (3, 1))
print('%.2f' % 3.1415926)
r = 2.5
s = 3.14 * r ** 2
print(f'The radius {
r} is {
s:.2f}')
list1 = ['Michael', 'Jack', ['asp', 'php'], 'Bob', 'Tracy']
print(list1[0])
print(list1[-1])
tuple1 = ('Michael', 'Bob', 'Tracy', ['A', 'B']) #['A', 'B']中可变,这是list
tuple2 = ('Michael', 'Bob', 'Tracy') #初始化后,不可变的
print('one:%s index:%s' % (tuple1[0], tuple1[0][0]))
s = set([1, 1, 2, 2, 3, 3])
print(s)
a = 'abc'
print(a.replace('a', 'A'))
basicStr()
input("basicStr:")
输出结果:
I'm ok.
I'm learning
Python.
\
\
\ \
line1
... line2
... line3
line1
line2
line3
hello,\n
world
True
False
True
3.3333333333333335
3
1
Hello, world
Hi, Michael, you have $1000000.
3-01
3.14
The radius 2.5 is 19.62
Michael
Tracy
one:Michael index:M
{
1, 2, 3}
Abc
一般函数等
#一般的函数
def function1():
print(abs(-20))
print(max(2, 3, 1, -5))
print(int('123'))
print(float('12.34'))
print(str(1.23))
print(bool(''))
print(bool(1))
function1()
####if、for循环
K=['Michael', 'Sarah', 'Tracy', 'Bob', 'Jack']
def way2(n):
r=[]
if n >= len(K):
pass
else:
for i in range(n):
r.append(K[i])
return r
print(way2(3))
print(way2(5))
print(way2(7))
####while循环
def way1(m):
L = []
n=1
while n<= m:
L.append(n)
n=n+2
return L
print(way1(20))
input("way1:")
输出结果
20
3
123
12.34
1.23
False
True
['Michael', 'Sarah', 'Tracy']
[]
[]
[1, 3, 5, 7, 9, 11, 13, 15, 17, 19]
函数示例
#nums为可变参数 如 (1,2,4)
def calc(*nums):
sum=0
for n in nums:
sum=sum+n*n
return sum
print(calc(5,