python3 _笨方法学Python_日记_DAY2

Day 2

• 习题  6:  字符串(string)和文本

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
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)

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.

加分题：

添加注释

# 定义x为一个字符串，其中用了整型%d的格式化字符
x = "There are %d types of people." % 10
# 定义binary和do_not 均为两个字符串
binary = "binary"
do_not = "don't"
# 格式化字符 %s 字符串，将binary和do_not字符串去掉引号，插入到新的字符串y中
y = "Those who know %s and those who %s." % (binary, do_not)
# 输出x和y
print(x)
print(y)
# 格式化字符%r 照原样打印，所以把x连带引号一起打印出来了
print("I said: %r." % x)
# 格式化字符%s 字符串，去掉了y中的引号，但是在打印的格式中，用引号把%s括起来了，所以最后还是显示有引号
print("I also said: '%s'." % y)
# 定义新变量，为布尔类型的值False
hilarious = False
# 定义字符串
joke_evaluation = "Isn't that joke so funny?! %r"
# 格式化字符%r 原样打印，布尔类型直接打印False
print(joke_evaluation % hilarious)
# 定义字符串w和e
w = "This is the left side of..."
e = "a string with a right side."
# 字符串相加就是连接起来
print(w+e)

• 习题  7:  更多打印

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

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,
      end7+end8+end9+end10+end11+end12)

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

 

• 习题  8:  打印，打印

formatter = "%r %r %r %r"

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 didn't sing.",
    "So I said goodnight."
))
# 换言之
formatter="'I had this thing.' 'That you could type up right.' 'But it didn't sing.' 'So I said goodnight.'"
print(formatter)
# 怎么不一样捏，第三个在前一种方案出现了双引号
# 原来是"But it didn't sing."这一句中已经出现了单引号，所以在格式化的时候为了避免认错，首尾换成了双引号

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 didn't sing." 'So I said goodnight.'
'I had this thing.' 'That you could type up right.' 'But it didn't sing.' 'So I said goodnight.'

python里使用单引号和双引号没有意思上的区别，当句中有单引号的时候会强制使用来双引号区分。

• 习题  9:  打印，打印，打印

# 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.
""")

　结果：

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.

三双引号可以放置多行文字

\n 为转义字符，换行

 

•  习题  10:  那是什么？

转义字符：

转义字符	意义	ASCII码值（十进制）
\a	响铃(BEL)	007
\b	退格(BS) ，将当前位置移到前一列	008
\f	换页(FF)，将当前位置移到下页开头	012
\n	换行(LF) ，将当前位置移到下一行开头	010
\r	回车(CR) ，将当前位置移到本行开头	013
\t	水平制表(HT) （跳到下一个TAB位置）	009
\v	垂直制表(VT)	011
\\	代表一个反斜线字符''\'	092
\'	代表一个单引号（撇号）字符	039
\"	代表一个双引号字符	034
\?	代表一个问号	063
\0	空字符(NULL)	000
\ooo	1到3位八进制数所代表的任意字符	三位八进制
\xhh	1到2位十六进制所代表的任意字符	二位十六进制

• 习题  11:  提问

age = input("How old are you?")
height = input("How tall are you?")
weight = input("How much do you weigh")

print("So, you are %r old, %r tall and %r heavy." % (age, height, weight))

How old are you?3
How tall are you?2
How much do you weigh1
So, you are '3' old, '2' tall and '1' heavy.

 

str = input("请输入：");
print ("你输入的内容是: ", str)