print ("Hello World!This is HDN's First python file!") #打印helloworld

what_he_does=' plays '

his_instrument='guitar'

his_name='Robert Johnson'

artist_intro=his_name+what_he_does+his_instrument

print(artist_intro) #打印并演示字符串相加

word='a loooooooong word'

num=12

string='bang!'

total=string*(len(word)-num)

print(len(word))

print(total) #演示len函数

phone_number='1370-939-4666'

hiding_number=phone_number.replace(phone_number[:9],'*'*9)

print(hiding_number) #演示string中的replace函数及字符串位数

def fahrenheit_converter(C):

fahrenheit=C*9/5+32

return str(fahrenheit)+'F'

C2F=fahrenheit_converter(35)

print(C2F) #打印转换成str的数字

def fahrenheit_converter2(C):

fahrenheit = C * 9/5 + 32

print(str(fahrenheit) + '°F')

C2F=fahrenheit_converter2(35)

print(C2F) #演示算术操作及赋值、打印

def gKg_converter(C):

gKg=C/1000

print(str(C)+"g = "+str(gKg)+" kg")

return

g2Kg=gKg_converter(3500)

print(' *',' * *',' * * *',' | ',sep='\n') #演示sep的用处，sep表示前述用，隔开字符串时，逗号插入什么动作。默认空

file=open('C://Users/HDN/PycharmProjects/Helloworld/text.txt','w')

file.write('Hello !! python world!') #演示打开并创建文件

def text_create(name,msg):

desktop_path='/Users/HDN/PycharmProjects/Helloworld/'

full_path=desktop_path+name+'.txt'

file=open(full_path,'w')

file.write(msg)

file.close()

print('Mission Accomplished!')

return

text_create('hello','This is python write function who say hello to you!And Python is case sensitive...')

#打开并创建文本文件，且写入特定信息。

def text_filter(word,censored_word='lame',changed_word='Awesome'):

return word.replace(censored_word,changed_word)

print(text_filter('Python is lame!'))

#替换字符

def censored_text_create(name,msg):

clean_msg=text_filter(msg)

text_create(name,clean_msg)

return

censored_text_create('Try','lame!lame!Python is lame!')

#按制定要求替换字符串

password_list = ['*#*#','12345']

def account_login():

password = input('Input your password:')

password_correct = password == password_list[-1]

password_reset = password == password_list[0]

if password_correct:

print('Login success!')

elif password_reset:

new_password = input('Enter your new password:')

password_list.append(new_password)

print('Your password has changed successfully!')

account_login()

else:

print('Wrong password or invalid input!')

account_login()

return

account_login()

count = 0

while True:

print('Repeat this line at '+str(count)+' times !')

count=count+1

if count==5:

break

print("No more prints!")

#接受字符输入并检查字符是否符合要求，利用了if elif else语句

import random #此段使用随机数，需要import random库

point1 = random.randrange(1,7)

point2 = random.randrange(1,7)

point3 = random.randrange(1,7)

print(point1,point2,point3)

import random

def roll_dice(numbers=3, points=None):

print('<<<<< ROLL THE DICE! >>>>>')

# if points is None:

points = []

while numbers > 0:

point = random.randrange(1,7)

print(point)

points.append(point)

numbers = numbers -1

return points

points_print=roll_dice()

print(points_print,'+',points_print[0],points_print[1],points_print[2],'+',sum(points_print))

#三个随机数，1<=point<7，学习random.randrange的用法

fruit = ['pineapple','pear']

fruit.insert(1,'grape')

fruit.append('grape')

print(fruit)

fruit.remove('grape')

print(fruit)

fruit[0:0]=['Orange']

print(fruit)

print(fruit[1:4])

#学习list列表的基本操作

num_list=[5,1,3,8,5,3,9,2,12]

print(sorted(num_list))

print(sorted(num_list,reverse=True))

#学习list列表的基本操作

a=[]

for i in range(1,11):

a.append(i)

print('a=',a)

b=[i for i in range(1,11)] #推导式，效率比上一段高

print('b=',b)

import time #以下代码可验证推导式的效率比标准for语句快多少，验证发现执行时间是前者的1/3

a=[]

t0=time.clock()

print(t0)

for i in range(1,2000000):

a.append(i)

print(time.clock()-t0,'seconds process time')

t0=time.clock()

b=[i for i in range(1,2000000)]

print(time.clock()-t0,"seconds process time")

z=[zimu.lower() for zimu in 'xyzABCDEFGHIJKLMN']

print(z)

#字符过滤器，读取特定txt文本，并统计各单词次数。注意，gbk与utf-8的异同。

#要读取非UTF-8编码的文本文件，需要给open()函数传入encoding参数，

#例如，读取GBK编码的文件,f = open('/Users/michael/gbk.txt', 'r', encoding='gbk')

#详情请看https://www.cnblogs.com/ymjyqsx/p/6554817.html

path = 'C://Users/HDN/PycharmProjects/Helloworld/splittext.txt'

with open(path,'r') as text:

words = text.read().split()

print(words)

for word in words:

print('{}-{} times'.format(word,words.count(word)))

class CocaCola:

formula = ['caffeine','sugar','water','soda']

def drink(self,name): #注意，类中的方法，必须有self参数（可用其他名字，习惯用self），且排第一。

print(name + ' got Energy! Such as : ',self.formula) #此处不加self则formula会报错为未定义。

username = input('Input your name:')

coke = CocaCola()

coke.drink(username)

#self的具体意义参看https://blog.csdn.net/ly_ysys629/article/details/54893185

class CocaCola:

formula = ['caffeine','sugar','water','soda']

def __init__(self): #_init_()是自动执行的

for element in self.formula:

print('Coke has {}!'.format(element))

def drink(self):

print('Energy!')

coke = CocaCola()

class TestA:

attr = 1

def __init__(self):

self.attr = 42

obj_a = TestA()

print(obj_a.attr)

import random

def fake_gender():

gender = random.choice(['男','女','变性'])

print('gender is ',gender)

fake_gender()

#以上代码均来自《编程小白的第一本python入门书》，作者：侯爵，感谢！下一步开始根据csdn上的简介来做爬虫。

#本helloworld到此结束。