python标准库之数据压缩

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python标准库提供了对通用压缩标准的支持。

python标准库提供了对通用压缩标准的支持。

一、zlib压缩标准

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import zlib
 
def zlib_demo1():
    '''
    对类字节对象进行压缩和解压
    '''
    data = b'test'
    # data = bytes('test', encoding = "utf8")
    # data = str.encode('test')

    com_bytes = zlib.compress(data)
    print("压缩后的数据: ", com_bytes)
 
    decom_bytes = zlib.decompress(com_bytes)
    print("解压后的数据: ", decom_bytes)

def zlib_demo2():
    '''
    对数据流进行压缩和解压
    '''
    # 数据流压缩
    with open("org_file.txt", "rb") as read, open("com_file.txt", "wb") as write:
        com = zlib.compressobj(level=9, memLevel=9)
        for data in read:
            write.write(com.compress(data))
        write.write(com.flush())
 
    # 对数据流进行解压
    with open("com_file.txt", "rb") as read, open("decom_file.txt", "wb") as write:
        decom = zlib.decompressobj()
        for data in read:
            write.write(decom.decompress(data))
        write.write(decom.flush())

zlib_demo1()
zlib_demo2()

二、gzip压缩标准

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import gzip
 
def gzip_demo1():
    '''
    对类字节对象进行压缩和解压
    '''
    data = b'test'
    # data = bytes('test', encoding = "utf8")
    # data = str.encode('test')

    com_bytes = gzip.compress(data)
    print("压缩后的数据: ", com_bytes)
 
    decom_bytes = gzip.decompress(com_bytes)
    print("解压后的数据: ", decom_bytes)

def gzip_demo2():
    '''
    对gzip文件的读写操作
    '''
    data = b'test'
    # 写入
    with gzip.open('1.gz', 'wb') as write:
        write.write(data)
    # 读取
    with gzip.open('1.gz', 'rb') as read:
        data2 = read.read()
        print(data2)

def gzip_demo3():
    '''
    对文件对象的压缩与解压
    '''
    import shutil
    # 压缩
    with open('org_file.txt', 'rb') as read, gzip.open('org_file.txt.gz', 'wb') as write:
        shutil.copyfileobj(read, write)
    # 解压
    with gzip.open('org_file.txt.gz', 'rb') as read, open('decom_file.txt', 'wb') as write:
        shutil.copyfileobj(read, write)

gzip_demo1()
gzip_demo2()
gzip_demo3()

三、bz2压缩标准

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import bz2
 
def bz2_demo1():
    '''
    对类字节对象进行一次性的压缩和解压
    '''
    data = b'test'
    # data = bytes('test', encoding = "utf8")
    # data = str.encode('test')

    com_bytes = bz2.compress(data)
    print("压缩后的数据: ", com_bytes)
 
    decom_bytes = bz2.decompress(com_bytes)
    print("解压后的数据: ", decom_bytes)

def bz2_demo2():
    '''
    对类字节对象进行增量的压缩和解压
    '''
    data = [b'test', b'apple']
    # 增量压缩
    com_bz2 = bz2.BZ2Compressor()
    com_bytes = com_bz2.compress(b'')
    for d in data:
        com_bytes += com_bz2.compress(d)
    com_bytes += com_bz2.flush()  # flush()结束压缩进程
    print("增量压缩: ", com_bytes)

    # 增量解压缩
    decom_bz2 = bz2.BZ2Decompressor()
    decom_bytes = decom_bz2.decompress(com_bytes)
    print("增量解压: ", decom_bytes)


def bz2_demo3():
    '''
    对文件对象的压缩与解压
    '''
    import shutil
    # 压缩
    with open('org_file.txt', 'rb') as read, bz2.open('org_file.txt.gz', 'wb') as write:
        shutil.copyfileobj(read, write)
    # 解压
    with bz2.open('org_file.txt.gz', 'rb') as read, open('decom_file.txt', 'wb') as write:
        shutil.copyfileobj(read, write)

bz2_demo1()
bz2_demo2()
bz2_demo3()

四、lzma压缩标准

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import lzma
 
def lzma_demo1():
    '''
    对类字节对象进行一次性的压缩和解压
    '''
    data = b'test'
    # data = bytes('test', encoding = "utf8")
    # data = str.encode('test')

    com_bytes = lzma.compress(data)
    print("压缩后的数据: ", com_bytes)
 
    decom_bytes = lzma.decompress(com_bytes)
    print("解压后的数据: ", decom_bytes)

def lzma_demo2():
    '''
    对类字节对象进行增量的压缩和解压
    '''
    data = [b'test', b'apple']
    # 增量压缩
    com_lzma = lzma.LZMACompressor()
    com_bytes = com_lzma.compress(b'')
    for d in data:
        com_bytes += com_lzma.compress(d)
    com_bytes += com_lzma.flush()
    print("增量压缩: ", com_bytes)

    # 增量解压缩
    decom_lzma = lzma.LZMADecompressor()
    decom_bytes = decom_lzma.decompress(com_bytes)
    print("增量解压: ", decom_bytes)


def lzma_demo3():
    '''
    对文件对象的压缩与解压
    '''
    import shutil
    # 压缩
    with open('org_file.txt', 'rb') as read, lzma.open('org_file.txt.xz', 'wb') as write:
        shutil.copyfileobj(read, write)
    # 解压
    with lzma.open('org_file.txt.xz', 'rb') as read, open('decom_file.txt', 'wb') as write:
        shutil.copyfileobj(read, write)

lzma_demo1()
lzma_demo2()
lzma_demo3()

五、zip压缩标准

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import zipfile
 
def zip_demo():
    # 创建压缩包
    with zipfile.ZipFile(r"file.zip", "a") as write:
        # 往压缩包里添加文件
        write.write("org_file.txt")
 
        # 测试压缩包
        error = write.testzip()
        if error:
            print("压缩文件错误: ", error)
            return
 
        # 打印压缩包信息
        write.printdir()
        write.close()
 
    # 解压压缩包
    with zipfile.ZipFile(r"file.zip", "r") as read:
        read.extractall("file")  # 解压缩目录
        read.close()

zip_demo()

六、tar压缩标准

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import tarfile
 
def tar_demo():
    # 创建压缩包
    with tarfile.open(r"file.tar", "w:gz") as write:
        # 往压缩包里添加文件
        write.add("org_file.txt")
        # 打印压缩包信息
        write.list()
 
    # 解压压缩包
    with tarfile.open(r"file.tar", "r:gz") as read:
        read.extractall("file")   # 解压缩目录

tar_demo()