Python 专题五 列表基础知识（二维list排序、获取下标和处理txt文本实例）

#list.sort(func=None, key=None, reverse=False) 
list = [4, 3, 9, 1, 5, 2] 
print list 
list.sort() 
print list 
#输出 
[4, 3, 9, 1, 5, 2] 
[1, 2, 3, 4, 5, 9] 

#sorted(list) 
list = ['h', 'a', 'p', 'd', 'i', 'b'] 
print list 
print sorted(list) 
print list 
#输出 
['h', 'a', 'p', 'd', 'i', 'b'] 
['a', 'b', 'd', 'h', 'i', 'p'] 
['h', 'a', 'p', 'd', 'i', 'b'] 

#list.sort(func=None, key=None, reverse=False) 
list = [('Tom',4),('Jack',7),('Daly',9),('Mary',1),('God',5),('Yuri',3)] 
print list 
list.sort(lambda x,y:cmp(x[1],y[1])) 
print list 
#输出 
[('Tom', 4), ('Jack', 7), ('Daly', 9), ('Mary', 1), ('God', 5), ('Yuri', 3)] 
[('Mary', 1), ('Yuri', 3), ('Tom', 4), ('God', 5), ('Jack', 7), ('Daly', 9)] 

#list.sort(func=None, key=None, reverse=False) 
list = [(1,93),(2,71),(3,89),(4,93),(5,85),(6,77)] 
print list 
list.sort(key=lambda x:x[1]) 
print list 
#输出 
[(1, 93), (2, 71), (3, 89), (4, 93), (5, 85), (6, 77)] 
[(2, 71), (6, 77), (5, 85), (3, 89), (1, 93), (4, 93)] 

#lambda [arg1[, arg2, ..., argN]]:expression 
f = lambda x,y,z:x+y+z 
num = f(1,2,3) 
print 'lambda: ' + str(num) 
#等价于 
def add(x,y,z): 
 return x+y+z 
num = add(1,2,3) 
print 'function: ' + str(num) 
#输出 
lambda: 6 
function: 6 

source = open("F:\\Student\\1Area.txt",'r') 
lines = source.readlines() 
L = [] #列表二维 国家行数 人口数 
count = 1 #当前国家在文件中第count行 
for line in lines: 
 line = line.rstrip('\n') #去除换行 
 .... #获取排名和面积 
 fNum = string.atof(number) #面积 
 L.append((count,ffNum)) #列表添加 
 count = count + 1 
else: 
 print 'End While' 
 source.close() 

L.sort(lambda x,y:cmp(x[1],y[1]),reverse = True) 
#遍历过程 表示第i名 (文件第x行,面积y平方公里) 
#重点 L[i]输出列表 1 (46, 17075200.0) L[i][0]表示元组tuple第一个数 1 46 
for i in range(len(L)): 
 print (i+1), L[i] 

line = line.rstrip('\n') #去除换行 
start = line.find(r'V:') 
end = line.find(r'平方公里') 
number = line[start+2:end] 
number = number.replace(',','') #去除',' 
#输出 
line => C:国家 E:中华人民共和国 A:国土面积 V:9,634,057或9,736,000平方公里（世界第3/4名） 
number => 9634057或9736000 

# coding=utf-8 
import time 
import re 
import os 
import string 
import sys 
 
source = open("F:\\Student\\1Area.txt",'r') 
lines = source.readlines() 
count = 1 
L = [] #列表二维 国家行数 人口数 
 
''''' 
第一部分 获取国土面积 
''' 
print 'Start!!!' 
for line in lines: 
 line = line.rstrip('\n') #去除换行 
 start = line.find(r'V:') 
 end = line.find(r'平方公里') 
 number = line[start+2:end] 
 number = number.replace(',','') #去除',' 
 fNum = 0.0 
 if '万' in number: 
 end = line.find(r'万') 
 newNum = line[start+2:end] 
 fNum = string.atof(newNum)*10000 
 else: #如何优化代码 全局变量 
 if '/' in number: 
 end = line.find(r'/') 
 newNum = line[start+2:end] 
 newNum = newNum.replace(',','') 
 fNum = string.atof(newNum) 
 elif '(' in number: 
 end = line.find(r'(') 
 newNum = line[start+2:end] 
 newNum = newNum.replace(',','') 
 fNum = string.atof(newNum) 
 elif '[' in number: 
 end = line.find(r'[') 
 newNum = line[start+2:end] 
 newNum = newNum.replace(',','') 
 fNum = string.atof(newNum) 
 elif '或' in number: 
 end = line.find(r'或') 
 newNum = line[start+2:end] 
 newNum = newNum.replace(',','') 
 fNum = string.atof(newNum) 
 elif ' ' in number: 
 end = line.find(r' ') 
 newNum = line[start+2:end] 
 newNum = newNum.replace(',','') 
 fNum = string.atof(newNum) 
 else: 
 fNum = string.atof(number) 
 #print line 
 #print number 
 #print fNum 
 L.append((count,fNum)) 
 count = count + 1 
else: 
 print 'End While' 
 source.close() 
 
''''' 
第二部分 从大到小排序 
参看 http://blog.chinaunix.net/uid-20775448-id-4222915.html 
''' 
L.sort(lambda x,y:cmp(x[1],y[1]),reverse = True) 
#print L 
#遍历过程 表示第i名 (文件第x行,面积y平方公里) 
#重点 L[i]输出列表 1 (46, 17075200.0) L[i][0]表示元组tuple第一个数 1 46 
for i in range(len(L)): 
 print (i+1), L[i] 
 
''''' 
第三部分 读写文件 
''' 
source = open("F:\\Student\\1Area.txt",'r') 
lines = source.readlines() 
result = open("F:\\Student\\1NewArea.txt",'w') 
count = 1 
for line in lines: 
 line = line.rstrip('\n') 
 #获取列表L中排名位置pm 
 pm = 0 
 for i in range(len(L)): 
 if count==L[i][0]: 
 pm = i+1 
 break 
 #获取文件中名次 
 if '世界第' in line: 
 start = line.find(r'世界第') 
 end = line.find(r'名') 
 number = line[start+9:end] 
 if '/' in number: #防止中国第3/4名 
 end = line.find(r'/') 
 number = line[start+9:end] 
 if '包括海外' in number: 
 number = '41' 
 print number,pm,type(number),type(pm) 
 
 if string.atoi(number)==pm: 
 line = line + ' 【排名正确】 【世界第' + str(pm) + '名】' 
 result.write(line+'\n') 
 else: 
 line = line + ' 【排名错误】 【世界第' + str(pm) + '名】' 
 result.write(line+'\n') 
 else: #文件中没有排名 
 line = line + ' 【新加排名】 【世界第' + str(pm) + '名】' 
 result.write(line+'\n') 
 count = count + 1 
else: 
 print 'End Sorted' 
 source.close() 
 result.close() 
 
''''' 
第四部分 输出一个排序好的文件 便于观察 
''' 
source = open("F:\\Student\\1Area.txt",'r') 
lines = source.readlines() 
result = open("F:\\Student\\1NewSortArea.txt",'w') 
#i表示第i名 L[i][0]表示行数 
pm = 0 
for i in range(len(L)): 
 pm = L[i][0] 
 count = 1 
 for line in lines: 
 line = line.rstrip('\n') 
 if count==pm: 
 line = line + ' 【世界第' + str(i+1) + '名】' 
 result.write(line+'\n') 
 break 
 else: 
 count = count + 1 
else: 
 print 'End Sorted Second' 
 source.close() 
 result.close()