python 代码笔记 0102

#!/usr/bin/env python

-- coding: utf-8 --

2.7版本要加的头

print ‘调用系统函数,方法’

abs() 取绝对值

print abs(-2)

比较函数 cmp()

print cmp(1,2)
print cmp(3,2)

print ‘自己定义函数,方法’

def func():
print ‘我的第一个Python函数’

hh = raw_input(‘名字是:’)

def get(x):
print x
get(0)

print ‘定义函数而不使用’
def fun():
pass

print ‘返回值’
def fu():
return 666778

print fu()

print help(abs)

print ‘类型转换’
ll = 666

print ‘整型’, int(ll)
print ‘浮点’, float(ll)
print ‘字符’, str(ll)
print ‘浮点’, unicode(ll)
print ‘布尔’, bool(ll)

print ‘类型判断’
print isinstance(2.0,int)

print ‘函数参数’

def han(l=[]):
l.append(‘end’)
return l

print han([5])
print han()
print han()

//第一种写法

def add(l=[]):
if l == None:
l.append(‘end’)
return l
else:
l = []
l.append(‘end’)
return l
print add()
print add()
print add()

print ‘# 第二种写法’
def add_f(l=[]):
if l != None:l = []
l.append(‘end’)
return l

print add_f()
print add_f()
print add_f()

第三种方式

def add_end(L=None):
if L is None:
L = []
L.append(‘END’)
return L
print add_end([1])
print add_end([2,3])
print add_end([4,5])

print ‘类型’
def num(number):
sun = 0
for x in number:
sun = sun + xx
return sun

print num()

print ‘扩展-参数’
def person(name, age, **kw):
print ‘name:’, name, ‘age:’, age, ‘other:’, kw

person(‘Bob’, 35, city=‘Beijing’)
person(‘Bob’, 35, aaa=666,lll=66699)

def func(a, b, c=0, *args, **kw):
print ‘a =’, a, ‘b =’, b, ‘c =’, c, ‘args =’, args, ‘kw =’, kw
func(1, 2)

一个*是元祖 两个是list

def fuu(name,age,money=5000,*akk,**kw):
print ‘名字是:’,name,‘年龄是:’,age,‘工资是:’,money,‘args是’,akk,‘kw是’,kw

fuu(‘张’,666)
fuu(‘张’,666)
fuu(‘张’,666,6000,‘ks’,aaa=666)

print ‘递归函数,简单点说就是调用自己’

def dg(x):
v = 0
if x > 10:
return x
return x*dg(x+1)

print dg(2)

注意的是 递归调用栈溢出