Python 基础 一

这里用的是 python 2.6

源于：http://wiki.jikexueyuan.com/project/learn-python-hard-way/

打印输出：

print “Hello World!”

注释： # A comment, this is so you can read your program later.

数字和数学计算：

print 3 + 2 + 1 - 5 + 4 % 2 - 1 / 4 + 6

变量和命名：

cars = 100

carpool_capacity = 100.0

print “There are”, cars, “cars available.”

print “We can transport”, carpool_capacity, “people today.”

字符串和文本：

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

打印输出：

1）

print “.” * 10 # ……….

2）

print 1,

print 2 ## 1 2

print 1 # 1

print 2 # 2

3）

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.”

)

转义：

“I am 6’2\” tall.” # 将字符串中的双引号转义

‘I am 6\’2” tall.’ # 将字符串中的单引号转义

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* Fishies

\t* Catnip\n\t* Grass

“”“

print tabby_cat

print persian_cat

print backslash_cat

print fat_cat

输出：

$ python ex10.py

I’m tabbed in.

I’m split

on a line.

I’m \ a \ cat.

I’ll do a list:

* Cat food

* Fishies

* Catnip

* Grass

输入信息：

print “How old are you?”,

age = raw_input()

print “How tall are you?”,

height = raw_input()

print “How much do you weigh?”,

weight = raw_input()

print “So, you’re %r old, %r tall and %r heavy.” % (

age, height, weight)

$ python ex11.py

How old are you? 38

How tall are you? 6’2”

How much do you weigh? 180lbs

So, you’re ‘38’ old, ‘6\’2”’ tall and ‘180lbs’ heavy.

想想为什么最后一行’6\’2”’ 里边有一个\’ 序列。单引号需要被转义，从而防止它被识别为字符串的结尾。

age = raw_input(“How old are you? “)

height = raw_input(“How tall are you? “)

weight = raw_input(“How much do you weigh? “)