Python變量學(xué)習(xí)

1.變量介紹

變量來源于數(shù)學(xué)，是計算機(jī)語言中能儲存計算結(jié)果或能表示值的抽象概念，變量可以通過變量名訪問，在指令式語言中，變量通常是可變的。

其中Teacher是變量名，zhangzexiang是變量值;

這句話意思是,把變量值zhangzexiang儲存在變量名Teacher中。

Teacher="zhangzexiang"  
print (Teacher)

2.用變量進(jìn)行計算

2.1 這個就是第1章 打印輸出 第2節(jié) 引號規(guī)則里面說的給變量名賦值。

a=6
b=4
print(a+b)

2.2 我們也可以將a+b的計算結(jié)果用c來代表，最后直接打印輸出c。

a=6
b=4
c=a+b
print(c)

2.3 不止是數(shù)字，字母也是可以進(jìn)行變量名賦值的。

a="zhang"
b="zexiang"
print(a+b)

2.4 自增自減

a=7
a=a-1
print (a)

3.大量練習(xí)

cars=100                  #汽車數(shù)量
space_in_a_car=4.0        #汽車空間
drivers=30                #司機(jī)數(shù)量
passengers=90             #拼車數(shù)量
cars_not_driven=cars-drivers   #空車數(shù)量=汽車數(shù)量-司機(jī)數(shù)量
cars_driven=drivers            #汽車驅(qū)動=司機(jī)數(shù)量
carpool_capacity=cars_driven*space_in_a_car      #拼車能力=汽車驅(qū)動*汽車空間
average_passengers_per_car=passengers/cars_driven  #平均每輛車的乘客=拼車數(shù)量/汽車驅(qū)動


print("There are",cars,"cars available.")   #有100輛汽車可用。
print("There are only",drivers,"drivers available.")#目前只有30名司機(jī)。
print("There will be",cars_not_driven,"empty cars today.")#今天將有70輛空車。
print("We can transport",carpool_capacity,"people today.")#我們今天可以運送120.0人。
print("We have",passengers ,"to carpool today.")#今天我們有90個拼車。
print("We need to put about",average_passengers_per_car,"in each car")#我們需要在每輛車?yán)镅b上3.0個座位

my_name='Zed A.Shaw'
my_age=35 # not a lie
my_height=74 # inches
my_weight=180 #Lbs
my_eyes="Blue"
my_teeth="White"
my_hair="Brown"


print("Let's talk about %s."%my_name)
print("He's %d inches tall."%my_height)
print("He's %d pounds heavy."%my_weight)
print("Actually that's not too heavy.")
print("He's got %s eyes and %s hair."%(my_eyes,my_hair))
print("His teeth are usually %s depending on the coffee."%my_teeth) # this line is tricky , try to get it exactly right
print("If I add %d,%d,%d I get %d."%(my_age,my_height,my_weight,my_age+my_height+my_weight))


'''
讓我們來討論一下Zed A.Shaw。
他的74英寸高。
他是180磅重。
實際上，這并不太重。
他有藍(lán)色的眼睛和棕色的頭發(fā)。
他的牙齒通常是白色的，這取決于咖啡。
如果加35,74,180得到289。
'''

x=("There are %d types of people."%10)
binary="binary"
do_not="don't"
y=("Those who know %s and those who %s."%(binary,do_not))
print(x)
print(y)
print("I said: %r." %x)
print("I also said:%s." %y)


hilarious=False  #滑稽的
joke_evaluation=("Isn't that joke so funny?! %r ")  #笑話評價
print(joke_evaluation%hilarious)


w=("This is the left side of")
e=(" a string with a right side.")
print(w+e)
'''
There are 10 types of people.
Those who know binary and those who don't.
I said: 'There are 10 types of people.'.
I also said:Those who know binary and those who don't..


Isn't that joke so funny?! False 
This is the left side of a string with a right side.


有10種類型的人。
知道二進(jìn)制的和不知道二進(jìn)制的。
我說:“有10種類型的人?！?我也說過:那些知道二進(jìn)制和不知道二進(jìn)制的人。


這個笑話好笑嗎?假
這是一個有右側(cè)的弦的左邊。
'''

print("Mary had a little lamb.")
print("Its fleece was white as %s." %'snow')
print("And everywhere that Mary went.")
print("."*10)# what'd that do?


end1="C"
end2="h"
end3="e"
end4="e"
end5="s"
end6="e"
end7="B"
end8="u"
end9="r"
end10="g"
end11="e"
end12="r"
## watch that comma at the end. try removing it to see what happens
print(end1+end2+end3+end4+end5+end6,end=" ")
print(end7+end8+end9+end10+end11+end12)


'''
Mary had a little lamb.
Its fleece was white as snow.
And everywhere that Mary went.
..........
Cheese Burger


瑪麗有只小羊羔。
它的羊毛像雪一樣白。
和瑪麗去的地方。
..........
奶酪漢堡。


'''

formatter=("%r %r %r %r")  #格式器


print (formatter %(1,2,3,4))
print(formatter%("one","two","three","four"))
print(formatter%(True,False,False,True))
print(formatter%(formatter,formatter,formatter,formatter))
print(formatter%("I had this thing.",
    "That you could type up right.",
    "But it did't sing.",
    "So I said goodnight."))


'''
1 2 3 4
'one' 'two' 'three' 'four'
True False False True
'%r %r %r %r' '%r %r %r %r' '%r %r %r %r' '%r %r %r %r'
'I had this thing.' 'That you could type up right.' "But it did't sing." 'So I said goodnight.'


print字符打錯了，  字符串換行的時候要加, 與""號。
'''

#Exercise
#Here's some new strange stuff,remember type it exactly.
days="Mon Tue Wed Thu Fri Sat Sun"
months="Jan\nFeb\nMar\nApr\nMay\nJun\njul\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.""")


'''
Here are the days: Mon Tue Wed Thu Fri Sat Sun
Here are the months: 
Jan
Feb
Mar
Apr
May
Jun
jul
Aug

 
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.




現(xiàn)在是這樣的日子:Mon Tue Wed Thu Fri Sat Sun
這里是幾月:
1月
2月
3月
4月
5月
6月
7月
8月

 
這里有一些東西。
三個雙引號。
我們可以輸入我們喜歡的東西。
即使是4行，也可以是5或6。
'''

## Exercise
tabby_cat="\tI'm tabbed in."
persian_cat="I'm split\non a line."
backslash_cat="I'm\\a\\cat."


fat_cat="""
I'll do a list:
\t*Cat food
\t*Flishies
\t*Catnip\n\t*Grass
"""
print(tabby_cat)
print(persian_cat)
print(backslash_cat)
print(fat_cat)


'''
    I'm tabbed in.
I'm split
on a line.
I'm\a\cat.


I'll do a list:
    *Cat food
    *Flishies
    *Catnip
    *Grass




'''