python压缩和解压缩模块之zlib的用法【python爬虫】

目录

• python压缩和解压缩模块之zlib
• python中zlib库用法
• zlib主要用于压缩与解压缩

>>> import zlib
>>> zlib.ZLIB_VERSION
"1.2.11"
>>> zlib.ZLIB_RUNTIME_VERSION
"1.2.11"

zlib.compress(data, level=-1)
zlib.decompress(data, wbits=MAX_WBITS, bufsize=DEF_BUF_SIZE)

>>> x = b"abcdefghijk"*100
>>> x0 = compress(x,0) 
>>> x1 = compress(x,1) 
>>> x9 = compress(x,9) 
>>> print(len(x),len(x0), len(x1), len(x9))
1100 1111 32 29 #无压缩时得到的数据比原始数据还大
>>> d1 = decompress(x9) #解压缩
>>> d1 == x
True

compressobj(level=-1, method=DEFLATED, wbits=MAX_WBITS, memLevel=DEF_MEM_LEVEL, strategy=Z_DEFAULT_STRATEGY[, zdict])

>>> zlib.adler32(b"abcdefghijk")
434701411
>>> zlib.crc32(b"abcdefghijk")
3461812127

import zlib
 
data = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz" 
       "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"
print(len(data))
print(data)
 
# 压缩
compressed_data = zlib.compress(data.encode())  # 注意：这儿要以字节的形式传入
print(len(compressed_data))
print(compressed_data)
 
# 解压
new_data = zlib.decompress(compressed_data).decode()
print(len(new_data))
print(new_data)

import zlib
 
 
# 压缩文件或数据
def compress_data(file, zip_file, level=9):
    file = open(file, "rb")
    zip_file = open(zip_file, "wb")
    compress = zlib.compressobj(level)
    data = file.read(1024)
    while data:
        zip_file.write(compress.compress(data))
        data = file.read(1024)
    zip_file.write(compress.flush())
    file.close()
    zip_file.close()
 
 
# 解压文件或数据
def decompress_data(zip_file, new_file):
    zip_file = open(zip_file, "rb")
    new_file = open(new_file, "wb")
    decompress = zlib.decompressobj()
    data = zip_file.read(1024)
    while data:
        new_file.write(decompress.decompress(data))
        data = zip_file.read(1024)
    new_file.write(decompress.flush())
    zip_file.close()
    new_file.close()
 
 
if __name__ == "__main__":
    file = "text.txt"
    zip_file = "text_zip.txt"
    compress_data(file, zip_file)
 
    new_file = "test_new.txt"
    decompress_data(zip_file, new_file)
    print("end!")