Python3学习笔记之基础教程二

fibo.py

__author__ = 'Administrator'
def fib(n):
    a,b=0,1
    while b        print(b,end=' ')
        a,b=b,a+b
    print()
def fib2(n):
    result=[]
    a,b=0,1
    while b        result.append(b)
        a,b=b,a+b
    return result
if __name__ == '__main__':
print('fibo.py 程序自身在运行')
else:
print('fibo.py来自另一模块')

__author__="xxx"

#http://www.w3cschool.cc/python3/python3-module.html

#模块的调用
import fibo
print(fibo.fib(1000))
print(fibo.fib2(100))

#直接把模块内（函数，变量的）名称导入到当前操作模块。
#但是那些由单一下划线（_）开头的名字不在此例
from fibo import fib,fib2
print(fib(500))
print(fib2(5000))

#每个模块都有一个__name__属性，当其值是'__main__'时，表明该模块自身在运行，否则是被引入。
if __name__ == '__main__':
print('程序自身在运行')
else:
print('我来自另一模块')
#dir() 函数会罗列出当前定义的所有名称:
print(dir())
print(dir(fibo))
import sys
print(dir(sys))
#格式化字符串
s = 'Hello, world.'
print(str(s))
print('We are the {} who say "{}!"'.format('knights', 'Ni'))
print('{0} and {1}'.format('spam', 'eggs'))
print('{1} and {0}'.format('spam', 'eggs'))
print('This {food} is {adjective}.'.format(food='spam', adjective='absolutely horrible'))
import  math
print(math.pi)
print('The value of PI is approximately %5.3f.' % math.pi)
#操作文件
import os
name="test.txt"
if os._exists(name):
    os.remove(name)
f = open(name, 'w+')
f.write('0123456789abcdef')
f.seek(0)
print(f.readline())
f.seek(5)     # 移动到文件的第六个字节
print(f.read(1))
#f.seek(-3, 2) # 移动到文件的倒数第三字节

f.close()
#try catch
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
def this_fails():
        x = 1/0
try:
    this_fails()
except ZeroDivisionError as err:
    print('Handling run-time error:', 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("fuck")
    # raise MyError(2*2)
except MyError as e:
    print('My exception occurred, value:', e.value)
#http://www.w3cschool.cc/python3/python3-errors-execptions.html

__author__="xxx"

#类定义
class people:
    #定义基本属性
    name = ''
    age = 0
    #定义私有属性,私有属性在类外部无法直接进行访问
    __weight = 0
    #定义构造方法
    def __init__(self,n,a,w):
        self.name = n
        self.age = a
        self.__weight = w
    def speak(self):
        print("%s is speaking: I am %d years old weight=%s" %(self.name,self.age,self.__weight))

p = people('tom',10,30)
p.speak()

#单继承示例
class student(people):
    grade = ''
    def __init__(self,n,a,w,g):
        #调用父类的构函
        people.__init__(self,n,a,w)
        self.grade = g
    #覆写父类的方法
    def speak(self):
        print("%s is speaking: I am %d years old,and I am in grade %d"%(self.name,self.age,self.grade))
s = student('ken',20,60,3)
s.speak()

#另一个类，多重继承之前的准备
class speaker():
    topic = ''
    name = ''
    def __init__(self,n,t):
        self.name = n
        self.topic = t
    def speak(self):
        print("I am %s,I am a speaker!My topic is %s"%(self.name,self.topic))

#多重继承
class sample(speaker,student):
    a =''
    def __init__(self,n,a,w,g,t):
        student.__init__(self,n,a,w,g)
        speaker.__init__(self,n,t)

test = sample("Tim",25,80,4,"Python")
test.speak()#方法名同，默认调用的是在括号中排前地父类的方法

#http://www.w3cschool.cc/python3/python3-stdlib.html
import os
print(os.getcwd())
print(dir(os))
#print(help(os))
import glob
print(glob.glob('*.py'))
import math
print(math.cos(math.pi / 4))

import random
print(random.choice(['apple', 'pear', 'banana']))
print( random.sample(range(100), 10))   # sampling without replacement
print(random.random())   # random float
print(random.randrange(6))    # random integer chosen from range(6)

from datetime import date
now = date.today()
print(now)