zlib主要用于压缩与解压缩
- 字符串:使用zlib.compress可以压缩字符串。使用zlib.decompress可以解压字符串。
- 数据流:压缩:compressobj,解压:decompressobj
示例代码:
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)
运行结果:
示例代码2:
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!')
运行结果:
注意:compressobj返回一个压缩对象,用来压缩不能一下子读入内存的数据流。 level 从9到-1表示压缩等级,其中1最快但压缩度最小,9最慢但压缩度最大,0不压缩,默认是-1大约相当于与等级6,是一个压缩速度和压缩度适中的level。