Python 上手

推荐网站：http://www.pythonclub.org/start Python俱乐部

数据类型：

#整型
integer_number = 90
 
#浮点
float_number = 90.4
 
#复数
complex_number = 10 + 10j
 
#list 序列
sample_list = [1,2,3,'abc']
 
#dictionary 字典
sample_dic = {"key":value, 2:3}
 
#tuple 只读的序列
sample_tuple = (1,3,"ab")
 
#嵌套
sample_nest = [(1,2,3),{1:2,3:4,'key':[1,2]},3]

 

条件判断结构：

flag1 = some_value
flag2 = other_value
if flag1:
  do_function_1()
elif flag2:
  do_function_2()
else:
  do_function_3()

循环结构：

for i in range(0, 10):
  print(i)

for i in ['a','b','c','dd','eee']:
  print(i)

Print 函数使用：

#直接出字符串
strHello = 'Hello Python' 
print strHello
#输出结果：Hello Python

#格式化输出整数
strHello = "the length of (%s) is %d" %('Hello World',len('Hello World'))
print strHello
#输出果：the length of (Hello World) is 11

#格式化输出十六进制数
nHex = 0x20
#%x --- hex 十六进制
#%d --- dec 十进制
#%d --- oct 八进制
print "nHex = %x,nDec = %d,nOct = %o" %(nHex,nHex,nHex)
#输出结果：nHex = 20,nDec = 32,nOct = 40
#使用整数的各个制打印同一个数

#格式化输出浮点数
import math
#default
print "PI = %f" % math.pi
#width = 10,precise = 3,align = left
print "PI = %10.3f" % math.pi
#width = 10,precise = 3,align = rigth
print "PI = %-10.3f" % math.pi
#前面填充字符
print "PI = %06d" % int(math.pi)
#输出结果
#PI = 3.141593
#PI =      3.142
#PI = 3.142
#PI = 000003
#浮点数的格式化，精度、度和

#格式化输出字符串
#precise = 3
print "%.3s " % ("jcodeer")
#precise = 4
print "%.*s" % (4,"jcodeer")
#width = 10,precise = 3
print "%10.3s" % ("jcodeer")
#输出结果：
#jco
#jcod
#jco
#同于字符串也存在精度、度和

#格式化输出列表
l = [1,2,3,4,'jcodeer']
print l
#输出结果：[1, 2, 3, 4, 'jcodeer']
#于list直接打印即可
'''6.出字典(dictionary)'''
d = {1:'A',2:'B',3:'C',4:'D'}
print d
#输出结果：{1: 'A', 2: 'B', 3: 'C', 4: 'D'}
#同python也是支持dictionary出的

#自动换行
#print 会自动在行末加上回车,如果不需回车，只需在print语句的结尾添加一个逗号”,“，就可以改变它的行为。
for i in range(0,5):
    print i,

#万能的%r
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."
 )

#输出结果：
$ python ex8.py
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.'
$