#1.1 安装Python
#1.1.1 Windows
#1.1.2 Linux和UNIX
#1.1.3 Macintosh
#1.1.4 其它公布版
#1.1.5 时常关注。保持更新
#1.2 交互式解释器
D:\>python
Python 2.7.5 (default, May 15 2013, 22:43:36) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> print "Hello, World!"
Hello, World!
>>> The Spanish Inquisition
File "<stdin>", line 1
The Spanish Inquisition
^
SyntaxError: invalid syntax
#1.3 算法是什么
#1.4 数字和表达式
>>> 2 + 2
4
>>> 53673 + 235253
288926
>>> 1/2
0
>>> 1.0/2.0
0.5
>>> from __future__ import division
>>> 1 / 2
0.5
>>> 1 // 2
0
>>> 1.0 // 2.0
0.0
>>> 1 % 2
1
>>> 10 / 3
3.3333333333333335
>>> 10 % 3
1
>>> 9 / 3
3.0
>>> 9 % 3
0
>>> 2.75 % 0.5
0.25
>>> 2 ** 3
8
>>> 3 ** 2
9
>>> (-3) ** 2
9
#1.4.1 长整数
>>> 1000000000000000000
1000000000000000000L
>>> 1000000000000000000L
1000000000000000000L
#1.4.2 十六进制和八进制
>>> 0xAF
175
>>> 010
8
#1.5 变量
>>> x = 3
>>> x * 2
6
#1.6 语句
>>> 2 * 2
4
>>> print 2*2
4
>>> x = 3
#1.7 获取用户输入
>>> input("The meaning of life: ")
The meaning of life: 42
42
>>> x = input("x: ")
x: 34
>>> y = input("y: ")
y: 42
>>> print x*y
1428
>>> if 1 == 2: print \'One equals two\'
...
>>> if 1 == 1: print \'One equals one\'
...
One equals one
>>> time = 120
>>> if time % 60 == 0: print \'On the hour!\'
...
On the hour!
#1.8 函数
>>> 2**3
8
>>> pow(2,3)
8
>>> 10 + pow(2, 3.5)/3.0
13.771236166328254
>>> 10 + pow(2, 3*5)/3.0
10932.666666666666
>>> abs(-10)
10
>>> 1/2
0
>>> round(1.0/2.0)
1.0
#1.9 模块
>>> import math
>>> math.floor(32.9)
32.0
>>> int(math.floor(32.9))
32
>>> from math import sqrt
>>> sqrt(9)
3.0
>>> foo=math.sqrt
>>> foo(4)
2.0
#1.9.1 cmath和复数
>>> sqrt(-1)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
ValueError: math domain error
>>> import cmath
>>> cmath.sqrt(-1)
1j
>>> (1+3j) * (9+4j)
(-3+31j)
>>> print "Hello, World!"
Hello, World!
>>> "Hello, world!"
\'Hello, world!\'
>>> "Let\'s go!"
"Let\'s go!"
>>> \'"Hello, world!" she said\'
\'"Hello, world!" she said\'
>>> \'Let\'s go！\'
File "<stdin>", line 1
\'Let\'s go。\'
^
SyntaxError: invalid syntax
>>> \'Let\'s go！\'
#1.9.2 回到__future__
#1.10 保存并执行程序
name=raw_input("What is your name?
")
print "Hello, " + name + "!"
raw_input("Press <enter>")
#1.10.1 通过命令提示符执行Python脚本
#1.10.2 让脚本像普通程序一样执行
D:\>python
Python 2.7.5 (default, May 15 2013, 22:43:36) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
#1.10.3 凝视
>>> import math
>>> pi = 3.14
>>> radius = 1.5
>>> print 2 * pi * radius
9.42
>>> # print the girth/perimeter of the circle
...
>>> user_name = raw_input("What is your name?
")
What is your name?Jonathan
>>> print user_name
Jonathan
#1.11 字符串
>>> print "Hello, world!"
Hello, world!
#1.11.1 单引號字符串和使引號转义
>>> "Hello, world!"
\'Hello, world!\'
>>> "Let\'s go!"
"Let\'s go!"
>>> \'"Hello, world!" she said\'
\'"Hello, world!" she said\'
>>> \'Let\'s go!\'
File "<stdin>", line 1
\'Let\'s go!\'
^
SyntaxError: invalid syntax
>>> \'Let\\'s go!\'
"Let\'s go!"
>>> "\"Hello, world!\" she said"
\'"Hello, world!" she said\'
#1.11.2 拼接字符串
>>> "Let\'s say " \'"Hello, world!"\'
\'Let\\'s say "Hello, world!"\'
>>> x="Hello,"
>>> y="wrold!"
>>> x+y
\'Hello,wrold!\'
>>> xy
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
NameError: name \'xy\' is not defined
>>> "Hello, " + "world!"
\'Hello, world!\'
#1.11.3 字符串表示。str和repr和反引號
#I guess repr means to reverse an expression
>>> "Hello, world!"
\'Hello, world!\'
>>> 10000L
10000L
>>> print "Hello, world!"
Hello, world!
>>> print 10000L
10000
>>> print repr("Hello, world!")
\'Hello, world!\'
>>> print repr(10000L)
10000L
>>> print str("Hello, world!")
Hello, world!
>>> print str(10000L)
10000
>>> print `"Hello, world!"`
\'Hello, world!\'
>>> print `10000L`
10000L
>>> temp = 42
>>> print "The temperature is " + temp
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: cannot concatenate \'str\' and \'int\' objects
>>> print "The temperature is " + `temp`
The temperature is 42
#1.11.4 input和raw_input的比較
>>> name = input("What is your name?")
What is your name?
Jon
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<string>", line 1, in <module>
NameError: name \'Jon\' is not defined
>>> name = input("What is your name?")
What is your name?"Jon"
>>> print "Hello, " + name + "!"
Hello, Jon!
>>> input("Enter a number" ")
File "<stdin>", line 1
input("Enter a number" ")
^
SyntaxError: EOL while scanning string literal
>>> input("Enter a number ")
Enter a number 3
3
>>> raw_input("Enter a number ")
Enter a number 3
\'3\'
#1.11.5 长字符串、原始字符串和Unicode
>>> print \'\'\'This is a very long string
... It continues here.
... And it\'s not over yet.
... "Hello, world!"
... Still here.\'\'\'
This is a very long string
It continues here.
And it\'s not over yet.
"Hello, world!"
Still here.
>>> """You can also use double quotes like this."""
\'You can also use double quotes like this.\'
>>> print "Hello, \
... world!"
Hello, world!
>>> 1+2+\
... 4+5
12
print \
\'Hello, world!\'
Hello, world!
>>> print \'Hello, \nworld!\'
Hello,
world!
>>> path = \'C:\nowhere\'
>>> path
\'C:\nowhere\'
>>> print path
C:
owhere
>>> print \'C:\\nowhere\'
C:\nowhere
>>> print path \'C:\\Program Files\\fnord\\foo\\bar\\frozz\\bozz\'
File "<stdin>", line 1
print path \'C:\\Program Files\\fnord\\foo\\bar\\frozz\\bozz\'
^
SyntaxError: invalid syntax
>>> print \'C:\\Program Files\\fnord\\foo\\bar\\frozz\\bozz\'
C:\Program Files\fnord\foo\bar\frozz\bozz
>>> print r\'C:\nowhere\'
C:\nowhere
>>> print r\'C:\Program Files\fnord\foo\bar\frozz\bozz\'
C:\Program Files\fnord\foo\bar\frozz\bozz
>>> print r\'Let\\'s go!\'
Let\\'s go!
>>> print r\'This is illegal\\'
File "<stdin>", line 1
print r\'This is illegal\\'
^
SyntaxError: EOL while scanning string literal
>>> print r"This is illegal\"
File "<stdin>", line 1
print r"This is illegal\"
^
SyntaxError: EOL while scanning string literal
>>> print r\'C:\Program Files\foo\bar\' \'\\\'
C:\Program Files\foo\bar\
>>> u\'Hello, world!\'
u\'Hello, world!\'
>>> u\'你好，世界。\'
u\'\u4f60\u597d\uff0c\u4e16\u754c\uff01\'
>>>
本章的新函数 abs(number) 返回数字的绝对值
cmath.sqrt(number) 返回平方根,也适用于负数
float(object) 将字符串和数字转换为浮点数
help() 提供交互式帮助
input(prompt) 获取用户输入
int(object) 将字符串和数字转换为整数
long(object) 将字符串和数字转换为长整数
math.cell(number) 返回数的上入整数,返回值的类型为浮点数
math.floor(number) 返回数的下舍整数,返回值的类型为浮点数
math.sqrt(number) 返回平方根,不适用于负数
pow(x,y[,z]) 返回x的y次幂(所得结果对z取模)
raw_input(prompt) 获取用户输入,返回的类型为字符串
repr(object) 返回该值的字符串表示形式
round(number[,ndidits) 依据给定的精度对数字进行四舍五入
str(object) 将值转换为字符串