用于記錄自己寫(xiě)的，或?qū)W習(xí)期間看到的不錯(cuò)的，小程序，持續(xù)更新......
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【例001】計(jì)算:1-2+3-4..+199-200值
復(fù)制代碼 代碼如下:
#encoding=utf-8
#計(jì)算 1-2+3-4..+199-200值
#1+3+5+7+...199
#-2-4-6...-200
sum1 = 0
sum2 = 0
for i in range(1,200,2): #計(jì)算1+3+5+7...199
sum1 +=i
print sum1
for i in range(-200,0,2): #計(jì)算-2+(-4)+(-6)...+(-200)
sum2 +=i
print sum2
print "The total of 1-2+3-4..+199-200 is: ", sum1+sum2
【例002】將兩個(gè)文件中相同的部分，寫(xiě)到一個(gè)文件中
復(fù)制代碼 代碼如下:
#encoding=utf-8
#Python 2.7.4
#Purpose: 將文件1.txt,2.txt中相同的內(nèi)容放到3.txt中;
f1 = open("1.txt","r+")
f2 = open("2.txt","r+")
f3 = open("3.txt","w+")
all1 = f1.readlines() #先拿文件1中所有行取出
all2 = f2.readlines() #再拿文件2中所有行取出
f1.close()
f2.close()
for l1 in all1:
for l2 in all2:
if l1.strip()==l2.strip(): #比較行中內(nèi)容是否一樣
f3.write(l2)
else:
continue
else:
pass
print "#"*40
f3.close()
【例003】反向讀取文件
假如要讀取的test.txt文件內(nèi)容如下:
復(fù)制代碼 代碼如下:
Python
Perl
Java
Shell
實(shí)現(xiàn)代碼:
復(fù)制代碼 代碼如下:
file1 = file('test.txt','r')
list1 = [] #用一個(gè)空列表用于存放每行的內(nèi)容
while True:
line = file1.readline()
list1.append(line.strip())
if len(line) == 0:
break
for l in list1[::-1]: #反向遍歷，然后依次讀取出來(lái)
print l
file1.close()
輸出結(jié)果:
復(fù)制代碼 代碼如下:
Shell
Java
Perl
Python
【例004】 往文件中所有添加指定的前綴
比如文中: print是一個(gè)函數(shù)
文本文件強(qiáng)制二進(jìn)制編碼
就變成了下面的
復(fù)制代碼 代碼如下:
01.Python 3.0: #print是一個(gè)函數(shù)
02.Python 3.0: #文本文件強(qiáng)制二進(jìn)制編碼
#coding = gbk #中文編碼
f_r = open('test.txt') #打開(kāi)要處理文件
f_w = open('file.txt','w') #創(chuàng)建要添加文件
i = 0 #加前綴標(biāo)志位
while True:
i += 1
line = f_r.readline()
if not line:
break
f_w.write('%02d'%(i) + '.Python 3.0: #' + line)#字符串格式化及拼接技巧
f_r.close() #關(guān)閉打開(kāi)的文件句柄
f_w.close()
【例005】
復(fù)制代碼 代碼如下:
#coding = gbk
'''''
下面code.txt文件中內(nèi)容，將
01 CN Chinese
02 IN India
03 HK HongKang
04 JP Japan
05 DE Germany
06 US United States of America
要文件的內(nèi)容，每一行文件，寫(xiě)到一個(gè)文件，且文件名前面兩個(gè)字段，如
文件名為:01_CN_Chinese.txt
文中內(nèi)容:01 CN Chinese
知識(shí)要點(diǎn):
1. ''.join 和 split函數(shù)
2. 字符的聯(lián)合
3. with語(yǔ)句,open文件
4. 遍歷數(shù)組
5. 切片操作
'''
postfix = '.txt' #設(shè)置后綴
with open('test.txt') as myfile: #with語(yǔ)句打開(kāi)文件為myfile
while True: #while循環(huán)拿文件讀出來(lái)
lines = myfile.readlines() #拿所有的行一次性讀取到列表中
if not lines: break #沒(méi)有則中斷
for line in lines: #遍歷列表
file_out = str('_'.join(line.split()[:])) + postfix #得到01_CN_Chinese.txt文件名
open(file_out,'w').write(line) #write(line),將沒(méi)行的文件寫(xiě)入新文件中
【例006】
復(fù)制代碼 代碼如下:
#coding = gbk
'''''
#最終實(shí)現(xiàn)下面的過(guò)程
foos = [1.0, 2.0, 3.0, 4.0, 5.0]
bars = [100, 200, 300, 400, 500]
1.0 [200, 300, 400, 500]
2.0 [100, 300, 400, 500]
3.0 [100, 200, 400, 500]
4.0 [100, 200, 300, 500]
5.0 [100, 200, 300, 400]
#知識(shí)點(diǎn)
1. map函數(shù)的理解
2. 關(guān)鍵是切片函數(shù)的應(yīng)用
'''
foos = [1.0, 2.0, 3.0, 4.0, 5.0]
bars = [100, 200, 300, 400, 500]
def func(foo):
index = foos.index(foo) #foo在foos中的索引，拿她取出來(lái)
print foo,bars[:][0:index] + bars[:][index+1:]
#該索引同樣在bars中相同位置，在切片的時(shí)候拿它取出，并拼接這個(gè)切片
#大功告成！
print map(func,foos)
【例007】求 6! + 5! + 4! + 3! + 2! + 1!
復(fù)制代碼 代碼如下:
def factorial(n):
return reduce(lambda x,y: x* y, range(1,n+1))#求6!
print reduce(lambda x,y: x + y, [factorial(i) for i in range(1,6)]) #求6! + 5! + 4! + 3! + 2! + 1!
【例008】 根據(jù)輸入打印文件
復(fù)制代碼 代碼如下:
import sys
helpinfo= '''''\
This program prints files to the standard output.
Any number of files can be specified.
Options include:
--[version|VERSION|V|v]: Prints the version number
--[help |HELP |H|h]: Display the help
'''
def readfile(filename):
try:
f = open(filename)
while True:
line = f.readline()
if not line:
break
print line,
except:
print 'some error here'
if len(sys.argv) < 2:
print 'No action is needed!'
sys.exit()
if sys.argv[1].startswith('--'):
option = sys.argv[1][2:]
if option in ['version','v','V','VERSION']:
print 'Version 1.0'
elif option in ['h','H','help','HELP']:
print helpinfo
else:
print 'Unknown option.'
sys.exit()
else:
for filename in sys.argv[1:]:
readfile(filename)
【例009】函數(shù)中args的用法
復(fù)制代碼 代碼如下:
def powersum(power,*args):
'''''Print each argument's power'''
total = 0
for item in args:
total += pow(item,power)
return total
print powersum(2,3,4) # (3**2) + (4**2)
print powersum(2,10) # 10**2
print powersum(2) # 0**2
【例010】匿名函數(shù)作為返回值
復(fù)制代碼 代碼如下:
def repeater(n):
print n
return lambda s: s*n
twice = repeater(2)
print twice('Hello')
print twice(5)
【例011】備份程序
復(fù)制代碼 代碼如下:
#!/usr/bin/env python
import os,time
source = ['/home/test/C','/home/test/shell'] #源文件目錄
target_dir = '/home/test/python' #目標(biāo)文件目錄
today = target_dir + time.strftime('%Y%m%d') #
now = time.strftime('%H%M%S')
if not os.path.exists(today): #判斷目錄是否存在
os.mkdir(today) #不存在的話(huà)則新建
print 'Successfully created directory', today
target = today + os.sep + now + '.zip' #target文件格式
zip_cmd = "zip -qr '%s' %s" % (target, ' '.join(source)) #-q:安靜模式 -r遞歸模式
#等價(jià)于 zip -qr /home/test/python20141202/142151.zip /home/test/C /home/test/shell
if os.system(zip_cmd) == 0: #判斷命令是否成功執(zhí)行，成功執(zhí)行，返回0
print 'Successful back to:', target
else: #失敗的話(huà)，打印信息
print 'Backup FAILED.'
加comment的版本
復(fù)制代碼 代碼如下:
#!/usr/bin/env python
import os,time
source = ['/home/test/C','/home/test/shell']
target_dir = '/home/test/python'
today = target_dir + time.strftime('%Y%m%d')
now = time.strftime('%H%M%S')
comment = raw_input('Enter comments here-->') #要輸入的comment
if len(comment) == 0: #如果沒(méi)有comment
target = today + os.sep + now + '.zip' #按照上面的操作執(zhí)行
else:
target = today + os.sep + now + '_' + comment.replace(' ','_') + '.zip'
#如果有comment,
if not os.path.exists(today):
os.mkdir(today)
print 'The backup directory created!', today
zip_command = "zip -qr '%s' %s" % (target, ' '.join(source))
if os.system(zip_command) == 0:
print 'Scuccessful backup to', target
else:
print 'The backup FAILED'
輸出結(jié)果 ：
復(fù)制代碼 代碼如下:
# python backup_ver4.py
Enter comments here-->add new example
The backup directory created! /home/test/python20141202
Scuccessful backup to /home/test/python20141202/145130_add_new_example.zip
【例012】將二進(jìn)制數(shù)轉(zhuǎn)為10進(jìn)制數(shù)
復(fù)制代碼 代碼如下:
def func(B):
I = 0
while B:
I = I * 2 + (ord(B[0])-ord('0'))
B = B[1:]
return I
b = raw_input('Enter binary here:')
print func(b)
【例013】將列表中排除重復(fù)項(xiàng)并將重復(fù)的項(xiàng)找出
復(fù)制代碼 代碼如下:
def find_duplicate(lst):
tmp = [] #臨時(shí)變量，存放排除后的列表
for item in lst:
if not item in tmp: #將不在tmp變量找出
tmp.append(item)
else:
print 'The duplicate item is:', item
print 'After remove the duplicate item:',
return tmp
if __name__=='__main__':
test = input("Enter List here:") #input技巧
print find_duplicate(test)
>>>
Enter List here:[2,1,4,2]
The duplicate item is: 2
After remove the duplicate item: [2, 1, 4]
【例014】用Python中列表中append()，pop()函數(shù)實(shí)現(xiàn)簡(jiǎn)單的堆棧方法:后進(jìn)先出
復(fù)制代碼 代碼如下:
l = []
l.append(1)
l.append(2)
l.append(3)
print l
print l.pop()
print l.pop()
print l.pop()
【例015】對(duì)列表中的單詞按首字母排序
復(fù)制代碼 代碼如下:
>>> words = ['apple','bat','bar','book','atom']
>>> tmp = {} #建個(gè)空字典
>>> for word in words:
letter = word[0] #作為字典中的鍵
if letter not in tmp: #判斷首字母是否存在于字典
tmp[letter] = [word] #注意要添加[],很關(guān)鍵
else:
tmp[letter].append(word) #如果鍵已經(jīng)存在，值列表添加
>>> tmp
{'a': ['apple', 'atom'], 'b': ['bat', 'bar', 'book']}
【例016】對(duì)文件進(jìn)行整理（除空格、TAB鍵、除#!&?等鍵），假如文本文件全為人名，并讓首字母大寫(xiě)
復(fù)制代碼 代碼如下:
john black
Jerry!
&alice
TOm#
south carolina###
mr smith?
代碼及輸出結(jié)果如下:
復(fù)制代碼 代碼如下:
import re
def clean(strings):
result = []
for value in strings:
value = value.strip()
value = re.sub('[#!&?]','',value)
value = value.title()
result.append(value)
return result
with open('data.txt','a+') as myfile:
lines = myfile.readlines()
for line in clean(lines):
print line
>>>
John Black
Jerry
Alice
Tom
South Carolina
Mr Smith
【例017】用while循環(huán)來(lái)判斷某個(gè)數(shù)是否是質(zhì)數(shù)
復(fù)制代碼 代碼如下:
y = input('Enter a integer Here:')
x = y / 2
while x > 1:
if y % x == 0:
print y, 'has factor', x
break
x -= 1
else:
print y, 'is prime'
【例018】用while實(shí)現(xiàn)搜索某個(gè)字符串的功能
復(fù)制代碼 代碼如下:
names = ['Tom','Alice','Wendy','Jerry','Bob','Smith']
while names:
if names[0] == 'Jerry':
print 'Hi,', names[0]
break
names = names[1:]
else:
print 'Not Found!'
【例019】對(duì)嵌套的序列進(jìn)行處理
復(fù)制代碼 代碼如下:
>>> T = ((1,2),(3,4),(5,6))
>>> for (a,b) in T:
... print a+100, b+200
...
101 202
103 204
105 206
【例020】用for循環(huán)實(shí)現(xiàn)查找
復(fù)制代碼 代碼如下:
source = ['sting',(3,4),100,0.1,[1,2]]
tests = [(3,4),3.14]
for t in tests: #先是遍歷小循環(huán)
for s in source: #再遍歷外層循環(huán)
if s == t:
print t, 'Found it! '
break
else: #else語(yǔ)句的位置非常關(guān)鍵，
print t, 'Not Found!'
等價(jià)于下面這種方式
復(fù)制代碼 代碼如下:
source = ['sting',(3,4),100,0.1,[1,2]]
tests = [(3,4),100,3.14]
for t in tests:
if t in source:
print t, 'Found it.'
else:
print t, 'Not found.'
【例021】用for循環(huán)來(lái)收集兩個(gè)序列中相同的部分
復(fù)制代碼 代碼如下:
seq1 = 'spam'
seq2 = 'suck'
res = []
for s1 in seq1:
if s1 in seq2:
res.append(s1)
print res
【例022】隔個(gè)取出字符串
復(fù)制代碼 代碼如下:
S = 'abcdefghijklmn'
for i in range(0,len(S),2):
print S[i],
#或者
print S[::2]
【例023】?jī)蓚€(gè)列表，列表中每個(gè)元素加100，然后與L1中對(duì)應(yīng)元素相乘，形成列表，再對(duì)列表求和
復(fù)制代碼 代碼如下:
L1 = [1,2,3,4]
L2 = [5,6,7,8] #L2每個(gè)元素加一百,105,106,107
#(5+100)*1 + (6+100)*2 + (100+7)*3 + (100+8)*4
# 合計(jì): 1070
L3 = [x+100 for x in L2]
L4 = []
for (x,y) in zip(L1,L3):
L4.append(x*y)
print sum(L4)
#或者用下面精簡(jiǎn)方式，只是剛看到有點(diǎn)頭痛!
print sum([x*y for x,y in [T for T in zip(L1,[x+100 for x in L2])]])
【例024】對(duì)列表進(jìn)行，合并，去重，取交集等操作
復(fù)制代碼 代碼如下:
def func(seq1, seq2=None, opra=None):
res = []
if opra == '-':
for item1 in seq1:
if item1 not in seq2:
res.append(item1)
elif opra == '&':
for item1 in seq1:
if item1 in seq2:
res.append(item1)
elif opra == '|':
tmp = seq1[:]
for item1 in seq2:
if item1 not in seq1:
tmp.append(item1)
return tmp
elif opra == '^':
for i in seq1:
if i not in seq2:
res.append(i)
for i in seq2:
if i not in seq1:
res.append(i)
return res
else:
print 'Need list as input!'
return res
L1 = [1,2,3,4]
L2 = [3,4,5,6]
print '[L1 - L2]:',func(L1,L2,'-')
print '[L1 & L2]:',func(L1,L2,'&')
print '[L1 | L2]:',func(L1,L2,'|')
print '[L1 ^ L2]:',func(L1,L2,'^')
def list_remove(seq):
res = []
for i in seq:
if i not in res:
res.append(i)
return res
L1 = [3,1,2,3,8]
print list_remove(L1)
def find_duplicate(seq):
res = []
for i in range(len(seq)):
if seq.count(seq[i]) >= 2:
print 'Found %s'% seq[i], 'The index is:', i
res.append(seq[i])
return res
L1 = [3,1,2,3,8]
print find_duplicate(L1)
結(jié)果如下:
復(fù)制代碼 代碼如下:
>>>
[L1 - L2]: [1, 2]
[L1 & L2]: [3, 4]
[L1 | L2]: [1, 2, 3, 4, 5, 6]
[L1 ^ L2]: [1, 2, 5, 6]
[3, 1, 2, 8]
Found 3 The index is: 0
Found 3 The index is: 3
[3, 3]
【例025】通過(guò)函數(shù)改變?nèi)肿兞康娜N方式
復(fù)制代碼 代碼如下:
var = 99
def local():
var = 0
def glob1():
global var
var += 1
def glob2():
var = 0
import Learn
Learn.var += 1
def glob3():
var = 0
import sys
glob = sys.modules['Learn']
glob.var += 1
def test():
print var
local();glob1();glob2();glob3()
print var
【例026】求range(10)中每個(gè)元素的立方
復(fù)制代碼 代碼如下:
def func():
res = []
for i in range(10):
res.append(lambda x, i=i: i ** x) #i=i這是關(guān)鍵，否則i默認(rèn)記憶最后一個(gè)值:9
return res
>>> res = func()
>>> for i in range(10):
res[i](3)
0
1
8
27
64
125
216
343
512
729
【例027】求最小值
復(fù)制代碼 代碼如下:
def min1(*args):
mini = args[0]
for arg in args[1:]:
if arg < mini:
mini = arg
return mini
def min2(first,*rest):
mini = first
for arg in rest:
if arg < first:
mini = arg
return mini
def min3(*args):
res = list(args)
res.sort()
return res[0]
print min1('c','a','b')
print min2(3,1,4)
print min3(1,'a',78,'c')
def func(test, *args):
res = args[0]
for arg in args[1:]:
if test(arg, res):
res = arg
return res
def lessthan(x, y): return x < y
def morethan(x, y): return x > y
print func(lessthan, 4,3,1,2,9)
print func(morethan, 4,3,1,2,9)
【例028】求多個(gè)集合的交集及合集
復(fù)制代碼 代碼如下:
def intersect(*args):
res = []
for x in args[0]:
for other in args[1:]:
if x not in other:
break
else:
res.append(x)
return set(res) #去除重復(fù)的部分
print intersect('SPAM','SCAM','SLAM')
def union(*args):
res = []
for seq in args:
for item in seq:
if not item in res:
res.append(item)
return res
print union('SA','SB','SC')
def intersect(*args):
res = []
for x in args[0]:
for other in args[1:]:
if x not in other:
break
else:
res.append(x)
#為了交互['S','S','A','A','M','M']
tmp = []
[tmp.append(i) for i in res if i not in tmp]
return tmp
print intersect('SCAM','SPAM','SLAM')
【例029】字典的拷貝及添加
復(fù)制代碼 代碼如下:
def copyDict(old):
new = {}
for key in old:
new[key] = old[key]
return new
def addDict(d1,d2):
new = {}
for key in d1.keys():
new[key] = d1[key]
for key in d2:
new[key] = d2[key]
return new
【例030】求質(zhì)數(shù)
復(fù)制代碼 代碼如下:
def isPrime(y):
if y < 1:
print y, 'not prime'
else:
x = y // 2
while x>1:
if y % x == 0:
print y, 'has factor', x
break
x -= 1
else:
print y, 'is prime!'
【例031】比較多個(gè)值的大小
復(fù)制代碼 代碼如下:
def min_max(func,*args):
res = args[0]
for arg in args[1:]:
if func(arg,res):
res = arg
return res
def min_func(x,y): return x < y
def max_func(x,y): return x > y
if __name__=='__main__':
print "The min value is:", min_max(min_func,4,3,2,1,7,6,9)
print "The max value is:", min_max(max_func,4,3,2,1,7,6,9)
# 輸出結(jié)果:
>>>
The min value is: 1
The max value is: 9
【例032】寫(xiě)一個(gè)小函數(shù)實(shí)現(xiàn)內(nèi)置函數(shù)dir的功能
復(fù)制代碼 代碼如下:
#Filename: mydir.py
tag = 1
def listing(module):
if tag:
print '-'*30
print 'name:', module.__name__,'file:', module.__file__
print '-'*30
count = 0
for attr in module.__dict__.keys():
if attr[0:2] == '__':
print '%02d) %s' % (count, attr)
else:
print getattr(module,attr)
count = count + 1
if tag:
print '-'*30
print module.__name__, 'has %d names.' % count
print '-'*30
if __name__=='__main__':
import mydir
listing(mydir)
【例033】求分?jǐn)?shù)平均值
復(fù)制代碼 代碼如下:
'''''Filename: grades.txt 求該文件中第二列的平均值
Jerry 78
Alice 45
Wendy 96
Tom 56
Bob 85
'''
temp = []
for line in open('grades.txt'):
a = line.strip().split()
if a:
temp.append(a[1])
#['78', '45', '96', '56', '85']
total = 0
for i in temp:
total += int(i)
print 'The total grade is:', total, 'The average is:', total/len(tmp)
【例034】一個(gè)實(shí)際類(lèi)的例子
復(fù)制代碼 代碼如下:
class GenericDisplay:
def gatherAttrs(self):
attrs = '\n'
for key in self.__dict__:
attrs += '\t%s=%s\n' % (key, self.__dict__[key])
return attrs
def __str__(self):
return '<%s: %s>' % (self.__class__.__name__, self.gatherAttrs())
class Person(GenericDisplay):
def __init__(self, name, age):
self.name = name
self.age = age
def lastName(self):
return self.name.split()[-1]
def birthDay(self):
self.age += 1
class Employee(Person):
def __init__(self, name, age, job=None, pay=0):
Person.__init__(self, name, age)
self.job = job
self.pay = pay
def birthDay(self):
self.age += 2
def giveRaise(self, percent):
self.pay *= (1.0 + percent)
if __name__ == '__main__':
bob = Person('Bob Smith', 40)
print bob
print bob.lastName()
bob.birthDay()
print bob
sue = Employee('Sue Jones', 44, job='dev', pay=100000)
print sue
print sue.lastName
sue.birthDay()
sue.giveRaise(.10)
print sue
【例035】根據(jù)給定的年月日以數(shù)字方式打印出日期(February 27th, 2015)
復(fù)制代碼 代碼如下:
# coding = UTF-8
#根據(jù)給定的年月日以數(shù)字形式打印出日期
months = [
'January' ,
'February',
'March' ,
'April' ,
'May' ,
'June' ,
'July' ,
'August' ,
'September',
'October' ,
'November' ,
'December'
]
#以1~31的數(shù)字作為結(jié)尾的列表
endings = ['st','nd','rd'] + 17 * ['th'] + \
['st','nd','rd'] + 07 * ['th'] + \
['st']
year = raw_input('Year: ')
month = raw_input('Month(1-12): ')
day = raw_input('Day(1-31): ')
month_number = int(month)
day_number = int(day)
#月份和天數(shù)減1來(lái)獲得正確的索引
month_name = months[month_number - 1]
ordinal = day + endings[day_number - 1]
print month_name + ' ' + ordinal + ', ' + year
#輸出結(jié)果
>>>
Year: 2015
Month(1-12): 2
Day(1-31): 27
February 27th, 2015
【例036】在居中的盒子里打印一條語(yǔ)句
復(fù)制代碼 代碼如下:
sentence = raw_input("Sentence: ")
screen_width = 80
text_width = len(sentence)
box_width = text_width + 6
left_margin = (screen_width - box_width) // 2
print ' '*left_margin + '+' + '-'*(box_width-4) + '+'
print ' '*left_margin + '| ' + ' '*(text_width) +' |'
print ' '*left_margin + '| ' + sentence +' |'
print ' '*left_margin + '| ' + ' '*(text_width) +' |'
print ' '*left_margin + '+' + '-'*(box_width-4) + '+'
#輸出結(jié)果
>>>
Sentence: Welcome To Beijing!
+---------------------+
| |
| Welcome To Beijing! |
| |
+---------------------+
【例037】簡(jiǎn)單小數(shù)據(jù)庫(kù)驗(yàn)證
復(fù)制代碼 代碼如下:
database = [
['Bob', '1234'],
['Tom', '2345'],
['Foo', '1478']
]
usr = raw_input('Enter username: ')
pwd = raw_input('Enter password: ')
if [usr, pwd] in database:
print 'Access Granted!'
else:
print 'Access Deny!'
【例038】使用給定的寬度打印格式化后的價(jià)格列表
復(fù)制代碼 代碼如下:
width = input('Please enter width: ')
price_width = 10
item_width = width - price_width
header_format = '%-*s%*s'
format = '%-*s%*.2f'
print '=' * width
print header_format % (item_width, 'Item', price_width, 'Price')
print '-' * width
print format % (item_width, 'Apples', price_width, 0.4)
print format % (item_width, 'Sweets', price_width, 0.5)
print format % (item_width, 'Pepper', price_width, 12.94)
print format % (item_width, 'Tender', price_width, 42)
print '-' * width
輸出格式:
復(fù)制代碼 代碼如下:
>>>
Please enter width: 30
==============================
Item Price
------------------------------
Apples 0.40
Sweets 0.50
Pepper 12.94
Tender 42.00
------------------------------
【例039】遍歷兩個(gè)對(duì)應(yīng)列表
復(fù)制代碼 代碼如下:
names = ['Alice', 'Bob' , 'Cherry', 'David']
numbers = ['0000' , '1111', '2222' , '3333' ]
for index,name in enumerate(names):
print '%-7s=> %s' % (name, numbers[index])
#輸出結(jié)果
>>>
Alice => 0000
Bob => 1111
Cherry => 2222
David => 3333
當(dāng)然也可以采用如下通常的做法:
復(fù)制代碼 代碼如下:
names = ['Alice','Bob', 'John', 'Fred']
ages = [27, 23, 31, 29]
for i in range(len(ages)):
print names[i],' is ', ages[i], ' years old!'
#輸出結(jié)果:
>>>
Alice is 27 years old!
Bob is 23 years old!
John is 31 years old!
Fred is 29 years old!
【例040】對(duì)存儲(chǔ)在小字典中數(shù)據(jù)進(jìn)行查詢(xún)
復(fù)制代碼 代碼如下:
peoples = {
'Alice':{
'phone' : '0948',
'address' : 'aaaa'
},
'Wendy':{
'phone' : '4562',
'address' : 'bbbb'
},
'David':{
'phone' : '4562',
'address' : 'bbbb'
}
}
#字典使用人名作為鍵。每個(gè)人用另外一個(gè)字典來(lái)表示，其鍵'phone'和'addr'分別表示他們的電話(huà)號(hào)碼和地址
labels = {
'phone' : 'phone number',
'address' : 'address'
}
#針對(duì)電話(huà)號(hào)碼和地址使用描述性標(biāo)簽，會(huì)在打印輸出時(shí)用到。
key = ''
name = raw_input('Name: ')
if name in peoples:
request = raw_input('Enter (p) or (a): ')
if request == 'p':
key = 'phone'
elif request == 'a':
key = 'address'
else:
print 'Please input p(phone) an a(address)!'
print "%s's %s is %s" % (name, labels[key],peoples[name][key])
else:
print 'Not Found!'
或者使用字典的get()方法，更好些。完整代碼如下:
復(fù)制代碼 代碼如下:
#字典使用人名作為鍵。每個(gè)人用另外一個(gè)字典來(lái)表示，其鍵'phone'和'addr'分別表示他們的電話(huà)號(hào)碼和地址
peoples = {
'Alice':{
'phone' : '0948',
'address' : 'aaaa'
},
'Wendy':{
'phone' : '4562',
'address' : 'bbbb'
},
'David':{
'phone' : '4562',
'address' : 'bbbb'
}
}
#針對(duì)電話(huà)號(hào)碼和地址使用描述性標(biāo)簽，會(huì)在打印輸出時(shí)用到。
labels = {
'phone' : 'phone number',
'addr' : 'address'
}
name = raw_input('Name: ')
#查找電話(huà)號(hào)碼還是地址?
request = raw_input('Phone number (p) or address (a)? ')
#查找正確的鍵
key = request #如果請(qǐng)求即不是p也不是a
if request == 'p': key = 'phone'
if request == 'a': key = 'addr'
#使用get()函數(shù)提供默認(rèn)值
person = peoples.get(name,{})
label = labels.get(key, key)
result = person.get(key, 'not available')
print "%s's %s is %s." % (name, label, result)
【例041】字典格式化字符串例子
復(fù)制代碼 代碼如下:
template='''''<html>
<head><title></title></head>
<h1>%(title)s</h1>
<p1>%(text)s</p1>
<body></body>
</html>'''
data = {'title':'My Home Page','text':'Welcome to my home page!'}
print template % data
#輸出結(jié)果:
>>>
<html>
<head><title></title></head>
<h1>My Home Page</h1>
<p1>Welcome to my home page!</p1>
<body></body>
</html>
【例042】需找100以?xún)?nèi)的最大平方數(shù)
復(fù)制代碼 代碼如下:
from math import sqrt
#從100開(kāi)始往下找，找到即停止，最大為: 81
for n in range(99, 0, -1):
root = sqrt(n)
if root == int(root):
print n
break
【例043】用while/True, break控制輸入
復(fù)制代碼 代碼如下:
while True: #一直進(jìn)行下去，除非break
word = raw_input('Please Enter a word: ')
if not word: break #輸入為空的話(huà)，中斷循環(huán)
print 'The word was: ' + word
【例044】將兩個(gè)列表中首字母相同的提取出來(lái)
復(fù)制代碼 代碼如下:
#將兩個(gè)列表中首字母相同的羅列在一起
girls = ['alice', 'bernice', 'clarice']
boys = ['chris', 'arnold', 'bob']
#列表推導(dǎo):
print [b+'+'+g for b in boys for g in girls if b[0] == g[0]]
#輸出結(jié)果:
>>>
['chris+clarice', 'arnold+alice', 'bob+bernice']
【例045】斐波那契數(shù)列求指定數(shù)字的列表
復(fù)制代碼 代碼如下:
def fibs(x):
fibs = [0, 1] # 初始值
for i in range(x):
# fibs[-2]+fibs[-1]：最新一個(gè)值是前面兩個(gè)值之和
# 并用append方法將其添加在后面
fibs.append(fibs[-2]+fibs[-1])
print fibs
if __name__=='__main__':
num = input('How many Fibonacci numbers do you want? ')
fibs(num)
或者用普通方法實(shí)現(xiàn):
復(fù)制代碼 代碼如下:
>>> def fib(max):
n, a, b = 0, 0, 1
tmp_list = []
while n < max:
tmp_list.append(a)
a, b = b, a+b
n += 1
return tmp_list
>>> fib(8)
[0, 1, 1, 2, 3, 5, 8, 13]
【例046】寫(xiě)一個(gè)自定義列表類(lèi)，讓它支持盡可能多的支持操作符號(hào)
復(fù)制代碼 代碼如下:
class MyList:
def __init__(self, start):
self.wrapped = [] # Make sure it's a list here
for x in start:
self.wrapped.append(x)
def __add__(self, other):
return MyList(self.wrapped + other)
def __mul__(self, time):
return MyList(self.wrapped * time)
def __getitem__(self, offset):
return self.wrapped[offset]
def __len__(self):
return len(self.wrapped)
def __getslice__(self, low, high):
return MyList(self.wrapped[low:high])
def append(self, node):
self.wrapped.append(node)
def __getattr__(self, name): # Other members: sort/reverse/etc
return getattr(self.wrapped, name)
def __repr__(self):
return repr(self.wrapped)
if __name__ == '__main__':
x = MyList('spam')
print x
print x[2]
print x[1:]
print x + ['eggs']
print x * 3
x.append('a')
x.sort()
for c in x:
print c,
# 輸出結(jié)果如下:
>>>
['s', 'p', 'a', 'm']
a
['p', 'a', 'm']
['s', 'p', 'a', 'm', 'eggs']
['s', 'p', 'a', 'm', 's', 'p', 'a', 'm', 's', 'p', 'a', 'm']
a a m p s
【例047】用urllib模塊來(lái)批量下載圖片
復(fù)制代碼 代碼如下:
import re
import urllib
def getHtml(url):
page = urllib.urlopen(url)
html = page.read()
return html
def getImg(html):
reg = r'src="(.*?\.jpg)" width'
imgre = re.compile(reg)
imgList = re.findall(imgre, html)
x = 0
for imgurl in imgList:
urllib.urlretrieve(imgurl, '%s.img' % x) # urlretrieve()下載圖片
x += 1
html = getHtml("http://www.w3cschool.cc/")
print getImg(html)
【例048】用PyQt4實(shí)現(xiàn)簡(jiǎn)單的按鈕事件（Hello,World!）
復(fù)制代碼 代碼如下:
# -*- coding: utf-8 -*-
import sys
from PyQt4 import QtCore, QtGui
# 自定義的窗口類(lèi)
class TestWindow(QtGui.QWidget):
# 窗口初始化
def __init__(self, parent = None):
super(TestWindow, self).__init__(parent)
self.setWindowTitle(u'胡桃?jiàn)A子')
# 創(chuàng)建按鈕
self.pushButton = QtGui.QPushButton(u'測(cè)試按鈕')
# 創(chuàng)建文本框
self.textEdit = QtGui.QTextEdit()
# 創(chuàng)建垂直布局
layout = QtGui.QVBoxLayout()
# 將控件添加到布局中
layout.addWidget(self.textEdit)
layout.addWidget(self.pushButton)
# 設(shè)置窗口布局
self.setLayout(layout)
# 設(shè)置按鈕單擊動(dòng)作
self.pushButton.clicked.connect(self.sayHello)
# 按鈕動(dòng)作處理
def sayHello(self):
self.textEdit.setText('Hello World!')
# 程序主入口
if __name__=='__main__':
app = QtGui.QApplication(sys.argv)
mainWindow = TestWindow()
mainWindow.show()
sys.exit(app.exec_())
【例049】用python解析文本的一個(gè)例子
假如配置文件如下, 要確保配置文件行為tablename后面的level中值給讀取出來(lái)
復(fù)制代碼 代碼如下:
#FileName: data.conf
(tablename "A__employee__id.sql")
(userid "000001")
(number "100001")
(level "P1")
(tablename "B__employee__id.sql")
(userid "100001")
(number "100000")
(level "P2")
(tablename "C_other_table.sql")
(userid "000001")
(number "100001")
(level "P2")
(tablename "C__employee__table.sql")
(userid "000001")
(number "100001")
(level "P3")
代碼如下:
復(fù)制代碼 代碼如下:
def parse_File(filename):
tmp = []
fh = open(filename)
line = fh.readline()
flag = 0
while line:
if "tablename" in line and "__employee__" in line:
count = 0
flag = 1
if flag == 1:
count += 1
if count == 4 and "level" in line:
value = line.split(r'"')[1]
tmp.append(value)
line = fh.readline()
return tmp
if __name__ == '__main__':
print parse_File('data.conf')
