One 、 Requirements describe

Write a Python Program , Every time you download a compressed file , Automatically decompress the internal files to the current folder and delete the compressed package , What we can learn from this case ：

• os Integrated application of modules
• glob Integrated application of modules
• utilize gzip zipfile rarfile tarfile Module decompression file

Two 、 Step analysis and pre knowledge

Code code before the need to interpret complex issues into a number of clear requirements , That is, the logic of the program implementation is ：

1. Check a folder regularly （ Such as download Folder ） Whether the compressed file exists
2. If there is a new compressed file, unzip it to a new folder in the current folder Delete compressed file
3. When it comes to compressed files, it is necessary to discuss different compression formats , There are mainly the following 4 Kind of ：

When it comes to compressed files, it is necessary to discuss different compression formats , There are mainly the following 4 Kind of ：

“.gz: namely gzip, Usually only one file can be compressed .tar: It's not a compression tool, it's a packaging tool , Can follow .gz Coordination formation .tar.gz Package compression format of .zip: and .tar.gz It's similar, but you can pack and compress multiple files .rar: Pack and compress files , Originally used for DOS ”

therefore , The judgment logic of whether the file is a compressed file can be as follows ：

1. Create a list of zip suffixes compressed_lst = ['gz', 'tar', 'zip', 'rar']
2. All file names in the target folder run filename.split(.)[-1] Get suffix
3. Determine whether the suffix is in compressed_lst in , If it exists, run the subsequent decompression code
4. If so gz Final document , After decompressing, we need to judge again whether it is with .tar ending , And deal with it accordingly

The decompression code of different compressed files is different , Expand the specific operation in the following code .

3、 ... and 、 Code implementation

The first is acquisition download File names of all files in the folder

import glob
import os
path = r'C:\xxxx\download'
file_lst = glob.glob(path + '/*')
# List derivation
filename_lst = [os.path.basename(i) for i in file_lst]
print(filename_lst)

Next, according to the suffix name of the file to determine whether it needs to be compressed , Let's take a look at the code framework

for i in filename_lst:
if '.' in i:
# Get suffix
suffix = i.split('.')[-1]
# Match the suffixes one by one with the compressed suffixes of each format
if suffix == 'gz':
pass
if ...: # Again, judge whether the new file name is with .tar ending
pass
if suffix == 'tar':
pass
if suffix == 'zip':
pass
if suffix == 'rar':
pass

Here you are 2 A note ：

1. Some files have no suffix , So there may not be ., Use filename.split('.')[-1] Will report a mistake , So we need to judge
2. With .gz Final document , After decompressing, we need to judge again whether it is with .tar ending , Then we can write the decompression code of the four kinds of compressed files into functions , It can be called separately when it meets the requirements

Handle .gz file

import gzip
def ungz(filename):
filename = filename[:-3] # gz The single file decompression of a file is to remove filename hinder .gz
gz_file = gzip.GzipFile(filename)
with open(filename, "w+") as file:
file.write(gz_file.read())
return filename # This gzip The function needs to return a value to further match untar function

As mentioned repeatedly before gz It's possible that the document is related to tar Document matching , So decompress gz After the file, we need to judge whether it is necessary to untie tar file

Here you can put tar The function of the file is written out ?

Handle .tar file

import tarfile
def untar(filename):
tar = tarfile.open(filename)
names = tar.getnames()
# tar It's a package of files , Unpacking produces a lot of files , So you need to create a folder to store
if not os.path.isdir(filename + "_dir"):
os.mkdir(filename + "_dir")
for name in names:
tar.extract(name, filename + "_dir/")
tar.close()

Handle .zip file

import zipfile
def unzip(filename):
zip_file = zipfile.ZipFile(filename)
# similar tar Unpack , Create a folder to store the extracted files
if not os.path.isdir(filename + "_dir"):
os.mkdir(filename + "_dir")
for names in zip_file.namelist():
zip_file.extract(names, filename + "_dir/")
zip_file.close()

Handle .rar file

import rarfile
def unrar(filename):
rar = rarfile.RarFile(filename)
if not os.path.isdir(filename + "_dir"):
os.mkdir(filename + "_dir")
os.chdir(filename + "_dir")
rar.extractall()
rar.close()

You can see , The four decompression codes are slightly different , I recommend you to experience the difference in the actual demonstration , Decompress and cooperate os.remove() You can delete the compressed package , Now let's look at the logic framework with the decompression function added ：

for filename in filename_lst:
if '.' in filename:
suffix = filename.split('.')[-1]
if suffix == 'gz':
new_filename = ungz(filename)
os.remove(filename)
if new_filename.split('.')[-1] == 'tar':
untar(new_filename)
os.remove(new_filename)
if suffix == 'tar':
untar(filename)
os.remove(filename)
if suffix == 'zip':
unzip(filename)
os.remove(filename)
if suffix == 'rar':
unrar(filename)
os.remove(filename)

Real time detection

The simpler way is to set up while True Dead loop coordination time.sleep() sleep , The framework is as follows ：

import time
while True:
func()
time.sleep(5) # Sleep seconds can be set a bit larger to avoid over using resources

Finally, change the implementation code of the second step into a function and put it in the loop framework to complete the requirement , The complete code is as follows

import glob
import os
import gzip
import tarfile
import zipfile
import rarfile
import time
path = r'C:\xxxx\download'
file_lst = glob.glob(path + '/*')
filename_lst = [os.path.basename(i) for i in file_lst]
def ungz(filename):
filename = filename[:-3]
gz_file = gzip.GzipFile(filename)
with open(filename, "w+") as file:
file.write(gz_file.read())
return filename
def untar(filename):
tar = tarfile.open(filename)
names = tar.getnames()
if not os.path.isdir(filename + "_dir"):
os.mkdir(filename + "_dir")
for name in names:
tar.extract(name, filename + "_dir/")
tar.close()
def unzip(filename):
zip_file = zipfile.ZipFile(filename)
if not os.path.isdir(filename + "_dir"):
os.mkdir(filename + "_dir")
for names in zip_file.namelist():
zip_file.extract(names, filename + "_dir/")
zip_file.close()
def unrar(filename):
rar = rarfile.RarFile(filename)
if not os.path.isdir(filename + "_dir"):
os.mkdir(filename + "_dir")
os.chdir(filename + "_dir")
rar.extractall()
rar.close()
def unzip_files():
for filename in filename_lst:
if '.' in filename:
suffix = filename.split('.')[-1]
if suffix == 'gz':
new_filename = ungz(filename)
os.remove(filename)
if new_filename.split('.')[-1] == 'tar':
untar(new_filename)
os.remove(new_filename)
if suffix == 'tar':
untar(filename)
os.remove(filename)
if suffix == 'zip':
unzip(filename)
os.remove(filename)
if suffix == 'rar':
unrar(filename)
os.remove(filename)
while True:
unzip_files()
time.sleep(5)

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