from collections import deque
#文件读写
f = open('./test.txt', 'w+')
f.write('terrible and fuck\n')
f.write('aaa and eee')
f = open('./test.txt', 'r')
print(f.readline())
f.close()
#函数
def fib(n):
"""Print a Fibonacci series up to n"""
a, b = 0, 1
while a < n :
print (a, end=' ')
a, b = b, a+b
print ()
fib(2000)
#参数，不定参数，关键字参数
def ask_ok(prompt, retries=4, complaint='Yes or no,please!'):
while True:
ok = input(prompt)
if ok in ('y','ye','yes'):
return True
if ok in('n', 'no', 'nope'):
return False
if retries < 0:
raise OSError('uncooperative user')
print(complaint)
#ask_ok('Do you really want to quit?')
def parrot(voltage, state='a stiff', action='voom', type='Norwegian Blue'):
print("--This parrot would'n t", action, end=' ')
print("if you put", voltage, 'volts through it')
print('--Lovely plumage, the', type)
print("-- It's", state, "!")
parrot(voltage=1000, action='VOOOOM')
parrot('a thousand', type='Red')
def cheeseshop(kind, *arguments, **keywords):
print("--Do you have any", kind, '?')
print("--I'm sorry, we're all out of", kind)
print("-" * 40)
for arg in arguments:
print(arg)
print("-" * 40)
keys = sorted(keywords.keys())
for kw in keys:
print(kw, ":", keywords[kw])
cheeseshop("Limburger", "It's very runny, sir.",
"It's really very runny, sir.",
shopkeeper='Michael Palin',
client='John Cheese',
sketch='Cheese Shop Sketch')
def concat(*args, sep='/'):
return sep.join(args)
print(concat('earth', 'mars', 'venus'))
#列表
a = [333, 66.23, 333, 444, 222, 111]
print(a.count(333), a.count(222))
a.insert(3, -1)
a.append(330)
print(a)
a.remove(333)
print(a)
a.reverse()
print(a)
a.sort()
print(a)
print(a.pop())
#栈
stack = [3, 4, 5]
stack.append(6);
print(stack.pop())
#队列
queue = deque(['Eric', 'John', 'Michael'])
queue.append('Terry')
queue.append('Graham')
print(queue.popleft())
print(queue)
#列表推倒式
squares = []
for x in range(10):
squares.append(x**2)
print(squares)
squares = list(map(lambda x:x**2, range(10)))
print(squares)
squares = [x**2 for x in range(10)]
print(squares)
#嵌套的列表推倒式
matrix = [
[1, 2, 3, 4],
[5, 6, 7, 8],
[9, 10, 11, 12]
]
newMatrix = [[row[i] for row in matrix] for i in range(4)]
print(newMatrix)
#del 语句
del matrix[0]
print(matrix)
#元组和序列，一个元组由数个逗号分隔的值组成
t = 12345, 54345, 'hello'
print(t[0])
u = t, (2,3,4,5)
print(u)
#集合
tel = {'jack': 323, 'sage':444}
tel['guido'] = 466
print(tel)
keys = list(tel.keys())
print(keys)
keys = sorted(keys)
print(keys)
#循环技巧
##--字典--
knights = {'gall': 'the pure', 'robin': 'the brave'}
for k, v in knights.items():
print(k,v)
#--序列--
for i, v in enumerate(['tic', 'tac', 'toe']):
print(i, v)
#--同时循环两个或更多的序列
questions = ['name', 'quest', 'favorite color']
answers = ['lancelot', 'the holy grail', 'blue']
for q, a in zip(questions, answers):
print('what is your {0}? It is {1}' . format(q, a))
#逆向循环
for i in reversed(range(1, 10, 2)):
print(i)
#深入条件控制
##while和if可以包含任意操作， in ,not in , is ,is not, and, or
#模块
import module
module.fib(2000)
print()
print(dir()) #注意该列表列出了所有类型的名称：变量，模块，函数，等等。
if __name__ == "__main__":
print('main')
#exception
while True:
try:
x = 10
#x = int(input('Please enter a number:'))
break
except ValueError:
print('Oops! That was no valid number, Try again..')
import sys
try:
f = open('test.txt')
s = f.readline()
i = int(s.strip())
except OSError as err:
print('OS error: {0}' . format(err))
except ValueError:
print('Could not convert data to an integer')
except:
print('Unexpected error:', sys.exc_info()[0])
raise
try:
raise NameError('hi there')
except NameError as err:
print(err)
#自定义异常
class MyError(Exception):
def __init__(self, value):
self.value = value
def __str__(self):
return repr(self.value)
try:
raise MyError(2*2)
except MyError as e:
print('my exception occurred, value:', e.value)
#raise MyError('oops')
#else 语句
def divide(x, y):
try:
result = x/y
except ZeroDivisionError:
print('division by zero')
else:
print('result is', result)
finally:
print('execution finally clause')
divide(2, 1)
#作用域和命名空间示例
def scope_test():
def do_local():
spam = 'local spam'
def do_nonlocal():
nonlocal spam
spam = 'nonlocal spam'
def do_global():
global spam
spam = 'global spam'
spam = 'test spam'
do_local()
print('After local assignment:', spam)
do_nonlocal()
print('After nonlocal assignment:', spam)
do_global()
print('After global assignment:', spam)
scope_test()
print('In global scope:', spam)
#类对象
class MyClass:
"""A simple example class"""
i = 12345
def __init__(self):
self.i = 8888
def f(self):
return self.i
obj = MyClass()
print(obj.f())
class Complex:
def __init__(self, realpart, imagpart):
self.r = realpart
self.i = imagpart
cc = Complex(3,43)
print(cc.i, cc.r)
#类属性的任何函数对象都为那个类的实例定义了一个方法。函数定义代码不一定非得定义在类中：也可以将一个函数对象赋值给类中的一个局部变量。例如:
def f1(self, x, y):
return min(x, x+y)
class C:
f = f1
def g(self):
return 'hello world'
h = g
ccc = C()
print(ccc.f(2, 4))
#继承
#函数 isinstance() 用于检查实例类型： isinstance(obj, int) 只有在 obj.__class__ 是 int 或其它从 int 继承的类型
#函数 issubclass() 用于检查类继承： issubclass(bool, int) 为 True，因为 bool 是 int 的子类
#super() 可以动态的改变解析顺序。这个方式可见于其它的一些多继承语言，类似 call-next-method，比单继承语言中的 super 更强大 。
#多继承
class Base1:
def b(self):
return False
class Base2:
def b(self):
return False
class DerivedClassName(Base1, Base2):
ccc = 'cccc'
def f(self):
return True
#私有变量
__update = 'aaa'
dd = DerivedClassName()
print(dd.ccc)
#迭代器
for element in [1, 2, 3]:
print(element)
for element in (1, 2, 3):
print(element)
for key in {'one':1, 'two':2}:
print(key)
for char in "123":
print(char)
for line in open("test.txt"):
print(line, end='')
#生成器
sum(i*i for i in range(10))
xvec = [10, 20, 30]
yvec = [7, 5, 3]
sum(x*y for x,y in zip(xvec, yvec))
#标准库
#1 操作系统
import os
print()
print(os.getcwd())
#2 文件通配符
import glob
print(glob.glob('*.py'))
#3 命令行参数
import sys
print(sys.argv)
#4 错误输出重定向和程序终止
#sys.stderr.write('warning, log file not found')
#5 字符串正则匹配
import re
print(re.findall(r'\bf[a-z]*', 'which foot or hand fell fastest'))
#6 数学
import math
print(math.cos(math.pi / 4.0))
import random
print(random.choice(['apple', 'pear', 'banana']))
#7 互联网访问
from urllib.request import urlopen
for line in urlopen('http://www.baidu.com'):
line = line.decode('utf-8')
if 'EST' in line or 'EDT' in line:
print(line)
#日期和时间
from datetime import date
now = date.today()
print(now)
#数据压缩
import zlib
s = b'witch which has which witches wrist watch'
print(len(s))
t = zlib.compress(s)
print(len(t))
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