【Python学习笔记】第030讲，文件系统 os
本帖最后由 qq33zz 于 2018-6-29 18:31 编辑动动手0
import os
all_files = os.listdir(os.curdir)
type_dict = {}
for each_file in all_files:
if os.path.isdir(each_file):
type_dict.setdefault('文件夹', 0)
type_dict['文件夹'] += 1
else:
ext = os.path.splitext(each_file)
type_dict.setdefault(ext, 0)
type_dict += 1
for each_type in type_dict.keys():
print('该文件夹下共有类型为【%s】的文件 %d 个' % (each_type, type_dict))
动动手1
import os #计算文件大小
all_files = os.listdir(os.curdir)
for each_file in all_files:
if os.path.isfile(each_file):
print('%s[%d]'%(each_file,os.path.getsize(each_file)))
elif os.path.isdir(each_file):
print('文件夹名：%s'%each_file)
import os
def defind(star_path,file_input):
os.chdir(star_path)
for each_file in os.listdir(os.curdir):
if each_file == file_input:
print(os.getcwd()+os.sep+each_file)
if os.path.isdir(each_file):
defind(each_file,file_input)
os.chdir(os.pardir)
star_path =input('请输入需要搜索的路径：')
file_input = input('请输入需要查找的文件名:' )
defind(star_path,file_input)
动动手2
import os #查找路径下指定后缀名
def defind(star_path,suffix):
os.chdir(star_path)
for each_file in os.listdir(os.curdir):
if os.path.splitext(each_file) in suffix:
file.write(os.getcwd()+os.sep+each_file+'\n')
if os.path.isdir(each_file):
defind(each_file,suffix)
os.chdir(os.pardir)
file = open('list.txt', 'a')
suffix = ['.txt','.py']
star_path = input('请输入需要查询的路径：')
defind(star_path,suffix)
动动手3
import os
def scan_file(key,user_input): #查找文件
txt_file=[]
all_file = os.walk(os.getcwd())
for i in all_file:
for each_file in i:
if os.path.splitext(each_file) == '.txt':
each_file=os.path.join(i,each_file)
txt_file.append(each_file)
for file in txt_file:
str_position = scan_line(file, key)
if str_position:
print('=================================================================')
print('在【%s】文件中发现【%s】关键词' % (file, key))
for k in str_position.keys():
if user_input in ['Y','y']:
print('关键字被发现在第【%s】行第【%s】个字符'%(k,str_position))
return txt_file
def scan_line(file1,key): #查找行
line_result = {}
count_line = 0
b = open(file1)
for each_line in b.readlines():
count_line += 1
if key in each_line:
line_result = scan_str(each_line,key)
b.close()
return line_result
def scan_str(line,key): #查找字符
str_result = []
while line.find(key) != -1:
str_result.append(line.find(key))
break
return str_result
key = 'MJ'
user_input = 'Y'
scan_file(key,user_input)
知识点：
1、python 把 0、空字符串、和none看成False。
2、return可以返回多个值。
3、os.walk()查找路径下所有文件包括子文件夹，返回一个三元组（dirpath目录路径，dirname目录下所有文件夹名，filename目录下所有文件名）。
4、os.curdir当前目录（没有参数）、￥os.chdir（）路径跳转、os.pardir上级路径、￥os.getcwd()获取当前路径名、os.sep输入\、￥os.listdir（）获取路径下所有文件
5、os.find()用于查找字符串在文件中的位置。差找不到返回-1
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