# f=open(r'C:\Users\xuyin\Desktop\test\wordcnt.txt','r') 这种也对
f=open('C:\\Users\\xuyin\\Desktop\\test\\wordcnt.txt','r')
print(f.read()) # 全部读取
f.seek(0,0) # 回到初始位置
print(f.read(4)) # 读前4个字符, 包括标点 1234
print(f.readline()) # 上一行代码结果接下去这一行 5678
print(f.tell())  #10 当前的位置 \n 也算入的
f.close()  # 关闭文件

with open(r'C:\Users\xuyin\Desktop\test\aaa.txt','r')as f:x1=f.read() #得到一个字符串print(type(x1))print(x1)f.seek(0,0)print(1)x2=f.readline()#得到第一行,形成字符串print(type(x2))print(x2)
#    f.seek(0,0),没有这行则读取剩下的全部行print(f.readlines()) #得到一个列表,每行作为一个元素

with open(r'C:\Users\xuyin\Desktop\test\aaa.txt','w+')as f:f.write('what do you like?\nboth')#清空原来的重新写f.writelines('123\n')#接着写,f.writelines('thank you')f.seek(0,0)print(1)print(f.read())

#从末尾开始写:
with open(r'C:\Users\xuyin\Desktop\test\aaa.txt','a+')as f:f.write('see you!')f.seek(0,0)print(f.read())

with open(r'C:\Users\xuying_fall\Desktop\test\try1.txt','r') as f1:str1=f1.readlines()for i in range(0,len(str1)):str1[i]=str(i+1)+''+str1[i]  # str()函数把数值转为字符串!
with open(r'C:\Users\xuying_fall\Desktop\test\try2.txt','w') as f2:f2.writelines(str1)

with open(r'C:\Users\xuying_fall\Desktop\test\try2.txt','r+') as f3:f3.write('winter')

f1=open(r'C:\Users\xuyin\Desktop\test\tell.txt','r')
f1.readline() # 跳过第一行
line1=f1.readlines()
f2=open(r'C:\Users\xuyin\Desktop\test\mail.txt','r')
f2.readline() # 跳过第一行
line2 = f2.readlines()
name1=[] # 新列表 用于存储
tel1=[]
name2=[]
mail2=[]
for line in line1:elements=line.split()name1.append(str(elements[0]))tel1.append(str(elements[1]))
for line in line2:elements=line.split()name2.append(str(elements[0]))mail2.append(str(elements[1]))lines=[] # 生成新数据
lines.append('姓名\ttelephone\tmailbox\n')for i in range(len(name1)):s=''if name1[i] in name2:j=name2.index(name1[i]) # name1[i]在name2中的下标s='\t'.join([name1[i],tel1[i],mail2[j]])s=s+'\n'else:s='\t'.join([name1[i],tel1[i],str('---')])s = s + '\n'lines.append(s)
print(1)
# 处理name2 中剩下的信息不全的(没有)
for i in range(len(name2)):s=''if name2[i] not in name1:s = '\t'.join([name2[i], str('---'), mail2[i]])s = s + '\n'lines.append(s)# 写入新文件中
f3=open(r'C:\Users\xuyin\Desktop\test\info_telmail.txt', 'w')
f3.writelines(lines)
f1.close()
f2.close()
f3.close()

# (三)利用字典实现词频统计
def process(line,wordcnt):line=replacepunctuations(line) # 用空格代替标点words=line.split()for i in words: # 从每一行获取每一个字母if i in wordcnt:wordcnt[i]+=1else:wordcnt[i]=1  # 新增一项该词汇
def  replacepunctuations(line):for ch in line:  # 遍历每一个单词if ch in '~?@#$,.[]{}'"":line=line.replace(ch,' ')return linef=open(r'C:\Users\xuying_fall\Desktop\test\wordcnt.txt','r') # 只读模式打开文件
wordcnt={} # 新建一个字典
for line in f:  #遍历每一个行process(line.lower(),wordcnt) # 全部小写, 不区分大小写了
pairs=list(wordcnt.items()) # 列表化
print(pairs)
items=[(x,y) for (y,x) in pairs] # 交换下顺序
items.sort() # 根据单词次数从小到大排列
print(items)
#[(1, 'can'), (1, 'hello'), (1, 'holiday'), (1, 'it'), (1, 'join'), (1, 'later'), # (1, 'like'), (1, 'me'), (1, 'will'), (2, 'do'), (3, 'you')]

#改变某个文件下的所有文件的文件名
import os
import time #用于计算运行时间
#'连接符'.join(list) 将列表组成字符串
def change_name(path):global i #用于统计处理的文件个数if not os.path.isdir(path) and not os.path.isfile(path):#检查给出的路径是否为一个文件或者目录return Falseif os.path.isfile(path):print(222)file_path = os.path.split(path) #分割出目录名与文件名lists = file_path[1].split('.') #分割出文件名称与文件的扩展名file_ext = lists[-1] #取出后缀名(列表切片操作)
#        print file_exttxt1=['txt','doc']if file_ext in txt1:#rename(old,new)  os.rename(path,file_path[0]+'/'+lists[0]+'_xy.'+file_ext)new_name=lists[0]print(new_name)  # aaaprint(type(new_name)) # <class 'str'>print(len(new_name)) #3new_name=new_name[0:len(new_name)-1]#删除名字的最后一个字母
new_name=new_name+'xy' #  新增两个字符print (new_name) # aaaxyos.rename(path,file_path[0]+'/'+new_name+'.'+file_ext)
#            print type(lists[0])
#            os.rename(path,file_path[0]+'/'+lists[0]+'_xy.'+file_ext)i+=1 #统计文件个数elif os.path.isdir(path):print(111)for x in os.listdir(path):#返回该目录下的所有文件与目录名print(x)change_name(os.path.join(path,x)) #os.path.join()在路径处理上很有用,用于合并目录

txt_dir = 'C:\\Users\\xuyin\\Desktop\\test\\aaa.txt'
txt_dir = txt_dir.replace('\\','/')
start = time.time()
i = 0
change_name(txt_dir)
c = time.time() - start
print('程序运行耗时:%0.2f'%(c))
print('总共处理了 %s 个文件'%(i))

os.path.splitext('C:\\Users\\xuyin\\Desktop\\test\\aaa.txt')
('C:\\Users\\xuyin\\Desktop\\test\\aaa', '.txt')

os.path.dirname('C:\\Users\\xuyin\\Desktop\\test\\aaa.txt')
'C:\\Users\\xuyin\\Desktop\\test'
os.path.basename('C:\\Users\\xuyin\\Desktop\\test\\aaa.txt')
'aaa.txt'

os.path.join('d','dd')
ans:
'd\\dd'