python 学习之 PythonAdvance2
#!/usr/bin/python#coding=utf-8
#循环设计
#范围函数
S = 'abcdefghijk' #a b c d e f g h i j k
for i in range(0, len(S), 2):#0 1 2 3 4 5 6 7 8 9 10 11
print S
print len(S)
#遍历数组
S = 'abcdefghijk'
for (index, char) in enumerate(S):
print index
print char
#多个等长的序列
ta =
tb =
tc = ['a', 'b', 'c']
for (a, b, c) in zip(ta, tb, tc):
print(a, b, c)
#分解聚合
ta =
tb =
# cluster
zipped = zip(ta,tb)
print (zipped)
# decompose
na, nb = zip(*zipped)
print(na, nb)
#循环对象
f = open('test.txt')
f.next()
f.next()
f.next()
f.next()
f.next()
f.next()
f.next()
for line in open('test.txt'):
print line
#生成器
def gen():
a = 100
yield a
a = a*8
yield a
yield 1000
for i in gen():
print i
def gen():
for i in range(4):
yield i
G = (x for x in range(4))
#表推导
L = []
for x in range(10):
L.append(x**2)
print L
L =
print L
#函数对象
#lambda函数
func = lambda x,y: x + y
print func(3, 4)
def func(x, y):
return x + y
print func(3, 4)
#函数作为参数传递
def test(f, a, b):
print 'test'
print f(a, b)
test(func, 3, 5)
def U(a, b, c):
print 'U'
print a(b, c)
U(func, 5, 6)
#map()函数,map()的功能是将函数对象依次作用于表的每一个元素
re = map((lambda x:x+3),)
print re
re = map((lambda x,y: x+y),,)
print re
#filter()函数,如果函数对象返回的是True，则该次的元素被储存于返回的表中
def func(a):
if a > 100:
return True
else:
return False
print filter(func, )
#reduce()函数,reduce可以累进地将函数作用于各个参数
print reduce((lambda x, y: x + y), )
#错误处理
re = iter(range(5))
try:
for i in range(100):
print re.next()
except StopIteration:
print 'here is end ',i
print 'HaHaHaHa'
'''
re = iter(range(5))
for i in range(100):
print re.next()
print 'HaHaHaHa'
try:
print(a*2)
except TypeError:
print("TypeError")
except:
print("Not Type Error & Error noted")
def test_func():
try:
m = 1/0
except NameError:
print("Catch NameError in the sub-function")
try:
test_func()
except ZeroDivisionError:
print("Catch error in the main program")
print 'Lalala'
raise StopIteration('this is error')
print 'Hahaha'
'''
#动态类型
a = 3
a = 'au'
print a
a = 5
b = a
a = a + 2
print a
print b
L1 =
L2 = L1
L1 = 1
print L1, L2
L1 =
L2 =L1
L1 = 10
print L2
#从动态类型看函数的参数传递
def f(x):
x = 100
print x
a = 1
f(a)
print a
def f(x):
x = 100
print x
a =
f(a)
print a
xl =
yl =
L =
print L
#通过参数传递，判断数字、字符串、list、tuple、词典等数据类型是否为可变数据对象
a = 2
b = '啊哈'
c =
d = (1, 2, 3)
e = {'tom': 11, 'sam': 57, 'lily': 100}
def num(x): #数字
x = 100
print x
num(a)
print a
def str(x): #字符串
x = 'ade'
print x
str(b)
print b
def list(x): #list
x = 100
print x
list(c)
print c
def tuple(x): #tuple
x = 100
print x
tuple(d)
raise StopIteration()
print d
def dic(x): #词典
x['tom'] = 100
print x
dic(e)
print e
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