4.26-python学习笔记（变量及命名、字符串、格式化字符串print,format,%...）

参考书目：《Learn Python The Hard Way》

cars=100
print('there are ',cars,'cars available.')
##练习5 更多变量打印
my_name='zxx'
my_age=22
my_height=162
my_weight='secret'
my_eyes='black'
my_teeth='white'
my_hair='black'
print("let's talk about %s."%my_name)
print("she's %d inches tall."%my_height)
print("she's weight is %s."%my_weight)
print("actully that's not too heavy.")
print("she's got %s eyes and %s hair."%(my_eyes,my_hair))
print("her teeth are usually %s depending on the coffe."%my_teeth)
print("if i add %d ,%d, i get %d."%(my_age,my_height,my_age+my_height))
print('%.2f'%2.6345) #保留两位小数（%后加.)
#%c    转换成字符（ASCII 码值，或者长度为一的字符串）
#%r    优先用repr()函数进行字符串转换（Python2.0新增）
#%s    优先用str()函数进行字符串转换
#%d / %i     转成有符号十进制数
#%u    转成无符号十进制数(阿拉伯数字1，2,3,4.....10)
#%o    转成无符号八进制数(0,1,2,...7;逢八进一）
#%x / %X    (Unsigned)转成无符号十六进制数（x / X 代表转换后的十六进制字符的大小写）
#%e / %E    转成科学计数法（e / E控制输出e / E）
#%f / %F    转成浮点数（小数部分自然截断）
#%g / %G    %e和%f / %E和%F 的简写
#%%    输出%
##练习6 字符串和文本
x="there are %d types of people."%10
binary='binary'
do_not="don't"
y="those who kown %s and those who %s."%(binary,do_not)
print(x)
print(y)
print("i said :%r."%x)
#将%r改成$s,x字符串输出的时候没有单引号，即%r输出有单引号
print("i also said :%s."%y)
hilarious=False
joke_evaluation="isn't that joke so funny?!%r"
print(joke_evaluation %hilarious)
w="this is the left side of..."
e="a string with a right side"
print(w+e) #字符串拼接
#字符串拼接其他方法：
print('%s%s'%(w,e))
##练习7 更多打印
print("marry had a little lamb.")
print("its fleece was white as %s."%'snow')
print("and everyone that mary went.")
print("."*10)  #打印十个.
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)  #在一行内打印，利用end参数end=""(无缝连接）end=" "(字符串间有空格）
##练习8 ：打印，打印
formatter="%r %r %r %r"
print(formatter %(1,2,3,4))
print(formatter %("one","two","three","four")
print(formatter %("i had this thing.",
                    "that you could type up right.",
                    "but it didn't sing",
                    "so i said goodnight.")
                    )
#调试不成功的代码69-75
##练习9 打印，打印，打印
days="mon tue wed thu fri sat sun"
months="jan\nfeb\nmar\napr\nmay\njun\njul\naug" #\n换行标识符
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 ba able to type as much as we like.
        even 4 lines if we want,or 5,or 6.
    """)
#"""三引号：打印多行字符串