初识python ex03-ex15
ex03:数字和数学计算
%求余
#ex03
print ("I will now count my chickens:")
print ("Roosters",100 - 25 * 3 % 4) # % 求余
print ("Now I will count the eggs:")
print (3 + 2 + 1 - 5 + 4 % 2 - 1 / 4 + 6 )
print (3 + 2 < 5 - 7)
print ("what is 3 + 2?",3 + 2)
print ("what is 5 - 7?",5 - 7)
ex04 变量
=赋值 ==左右两边相等，返回bool值
cars = 100
space_in_a_car =4.0
drivers = 30
passengers = 90
cars_not_driven = cars - drivers
cars_driven = drivers
carpool_capacity = cars_driven * space_in_a_car
average_passengers_per_car = passengers / cars_driven
print ("There are","cars available.")
print ("There are only",drivers,"drivers available.")
print ("we can transport", carpool_capacity,"people today.")
print ("we have", passengers, "to carpool today.")
print ("we need to put about", average_passengers_per_car, "in each car.")
ex05 更多的变量和打印
f 格式化字符串
my_name = "zed a. xiao"
my_age = 35 #not a lie
my_height = 175
my_weight = 75
my_eyes = "Black"
my_teeth = 'White'
my_hair = 'Brown'
print (f"Let's talk aboult {my_name}. ")
print (f"He's {my_weight} pounds heavy.")
print ("Actually that's not too heavy.")
print (f"he's got {my_eyes} eyes and {my_hair} hair")
print (f"His teeth are usually {my_teeth} depending on the coffee.")
total = my_age + my_height +my_weight
print (f"If I add {my_age},{my_height}, and {my_weight} I get {total}.")
ex06字符串和文本
.format()语法的格式化方式
types_of_pople = 10
x = f"There are {types_of_pople} types of people."
binary = "binary"
do_not = "don't"
y = f"Those who know {binary} and those who {do_not}."
print (x)
print (y)
print (f"I said: {x}")
print (f"I also said: '{y}' ") # ""套""报错
hilarious = "False"
joke_evaluation = "Is't that joke so funny?! {}"
print (joke_evaluation.format(hilarious))
w = "This is the left side of ..."
e = "a string with a right side."
print (w + e)
ex07 更多的打印
print ("Mary had a little lamb.")
print ("It's fleece was whilte as... {}....".format('snow'))
print ("." * 50) #what'd that do? 打印50个.
end1 = "c"
end2 = "h"
end3 = "e"
end4 = "e"
end5 = "s"
end6 = "e"
end7 = "B"
end8 = "u"
end9 = "r"
end10 = "g"
end11 = "e"
end12 = "r"
print (end1 + end2 + end3 + end4 + end5 + end6,end ='......')
print (end7 + end8 + end9 + end10 + end11 + end12)
ex08 打印 打印
对字符串做更复杂的格式化
formater = "{} {} {} {}"
print (formater.format(1 , 2 , 3 , 4))
print (formater.format("One" , "Two" , "three" , "four"))
print (formater.format(True , False , True ,False))
print (formater.format(formater , formater , formater , formater))
print (formater.format(
"try your",
"own text here",
"maybe a poem",
"or a song about fear"
))
ex09 打印，打印，打印
days = "Mon Tue Wed Fir Sat Sun"
months = "\nJan \nFeb \nMay \nJun \nAug"
print ("here are the days:",days)
print ("here are the months:",months)
print ("""
there's something going on here.
with the three double-quotes.
we'll be able to type as much as we like.
Even 4 lines if we want, or 5 ,or 6.
""")
#""" """ 多字符串引用
ex10 那是什么
tabby_cat = "\tI'm tabbed in."
persian_cat = "I'm spit\non a line."
backslash_cat = "I'm \\ a \\ cat."
fat_cat = """
I'll do a list:
\t* Cat food
\t* Fishies
\t* Catnip\n\t* Grass
"""
print (tabby_cat)
print (persian_cat)
print (backslash_cat)
print (fat_cat)
转义序列
| 转义字符 | 功能 |
|---|---|
| \\ | 反斜杠 |
| \* | 单引号 |
| \" | 双引号 |
| \n | 换行符 |
| \t | 水平制表符tab |
| \r | 回车符 |
| \a | ASCII响铃符 |
| \b | ASCII退格付符 |
| \f | ASCII进纸符 |
| \N | Unicode数据库中的字符名 |
| \uxxxx | 值为16位进制xxxx的字符 |
| \Uxxxxxx | 值为32位十六进制xxxxxx的字符 |
| \ooo | 值为八进制值ooo的字符 |
| \xhh | 值为十六进制值hh的字符 |
ex11 提问
input() 函数接受一个标准输入数据，返回为str字符串类型。
raw_input （）直接读取控制台的输入（任何类型的输入它都可以接收*
print ("How old are you?", end = ' ') # end= ' ' 占空位符
age = input()
print ("How tall are you ?",end = ' ')
height = input ()
print ("How much do you weight?",end = " ")
weight = input ()
print (f"so,you're {age} old , {height} tall and {weight} heavy.")
ex12 提示别人
y = input (""name?")
age = input ("How old are you? ")
height = input ("How tall are you ? ")
weight = input ("How much do you weight? ")
print (f"so.you're {age} old , {weight} tall and {weight} heavy.")
ex13 参数、解包和变量
#import将python模块（一种特性）引入到脚本的方法；
#argv 参数变量（argument variable）
from sys import argv
# read the WYSS section for how to run this
xxx, first, second, third = argv #argv解包，将其赋值给4个变量
print ("The script is called:", xxx) #打印出脚本文件名，可变
print ("Your fist variable is :", first)
print ("Your second variable is :", second)
print ("Your third variable is :", third)
#执行 python ex13.py 1nd 2nd 3nd 对应 xxx，first, second, third
- argv和input()的不同点：
用户输入的时机不同。如果参数在用户执行命令时就要有，那就用argv，如果在脚本运行过程中需要用户输入，那就用 input()
ex14 提示和传递
from sys import argv
script, user_name = argv
prompt = '>'
print (f"Hi {user_name} , I'm the {script} script.")
print ("I'd like ask you a few questions.")
print (f"Do you Like me {user_name} ?")
likes = input(prompt) #给了个输入提示符>
print (f"Where do you live {user_name} ?")
lives = input(prompt)
print ("What kind of computer do you have?")
computer = input(prompt)
print (f"""
Alright, so you said {likes} about liking me.
You live in {lives}. Not sure where that is.
And you have a {computer} computer. nice
""")
ex15 读取文件
#ex15 需要新建一个txt文件
from sys import argv
script, filename = argv #filename 运行时给与txt 文件名
txt = open (filename)
# open 接收一个参数并返回一个值，将一个值赋给一个变量，这就是打开文件过程。
print (f"Here's your file {filename}:")
print (txt.read ()) #嘿，txt执行你的read命令！
print ("Type the filename again:")
file_again = input ('>>>')
txt_again = open (file_again)# open (input('>'))
print (txt_again.read())
#处理完后需要将文件关闭。
txt.close ()
txt_again.close ()
