Python之gzip模块的使用

#!/usr/bin/env python3
# encoding: utf-8

import gzip
import io
import os

out_file_name = "example.text.gz"
with gzip.open(out_file_name, ‘wb‘) as output:
    with io.TextIOWrapper(output, encoding=‘utf-8‘) as enc:
        enc.write(‘test gzip content‘)
print(out_file_name, ‘包含的大小:{}bytes‘.format(os.stat(out_file_name).st_size))
os.system(‘file -b --mime {}‘.format(out_file_name))

#!/usr/bin/env python3
# encoding: utf-8

import gzip
import io
import os
import hashlib

def get_hash(data):
    """返回md5值"""
    return hashlib.md5(data).hexdigest()

# 读取文件内容，并且复制1024份出来
data = open(‘content.txt‘, ‘r‘).read() * 1024

# 输入文件内容，返回md5值
check_sum = get_hash(data.encode(‘utf-8‘))

print(‘Level  Size        Checksum‘)
print(‘-----  ----------  ---------------------------------‘)
print(‘data   {:>5}      {}‘.format(len(data), check_sum))

for i in range(0, 10):
    file_name = ‘compress-level-{}.gz‘.format(i)
    with gzip.open(file_name, ‘wb‘, compresslevel=i) as output:
        with io.TextIOWrapper(output, encoding=‘utf-8‘) as enc:
            enc.write(data)
    size = os.stat(file_name).st_size
    check_sum = get_hash(open(file_name, ‘rb‘).read())
    print(‘   {}   {:>4}        {}‘.format(i, size, check_sum))

#!/usr/bin/env python3
# encoding: utf-8

import gzip
import io
import itertools

with gzip.open(‘example_line.txt.gz‘,‘wb‘) as output:
    with io.TextIOWrapper(output,encoding=‘utf-8‘) as enc:
        enc.writelines(
            itertools.repeat(‘The same line\n‘,10) #重复写入10次
        )

#!/usr/bin/env python3
# encoding: utf-8

import gzip
import io

with gzip.open(‘example.text.gz‘, ‘rb‘) as input_file:
    with io.TextIOWrapper(input_file, encoding=‘utf-8‘) as dec:
        print(dec.read())

#!/usr/bin/env python3
# encoding: utf-8

import gzip
import io

with gzip.open(‘example.text.gz‘, ‘rb‘) as input_file:
    print(‘读取整个压缩文件的内容‘)
    all_data = input_file.read()
    print(all_data)
    expected = all_data[5:10]  # 切片取值
    print(‘切片取值：‘, expected)

    # 将流文件的指针切至起始点
    input_file.seek(0)

    # 将流文件的指针切至5的下标
    input_file.seek(5)

    new_data = input_file.read(5)
    print(‘移动指针取值：‘, new_data)
    print(‘判断两种取值是否一样：‘,expected == new_data)

#!/usr/bin/env python3
# encoding: utf-8

import gzip
from io import BytesIO
import binascii

# 获取未压缩的数据
uncompress_data = b‘The same line,over and over.\n‘ * 10
print(‘Uncompressed Len:‘, len(uncompress_data))
print(‘Uncompress Data:‘, uncompress_data)

buffer = BytesIO()
with gzip.GzipFile(mode=‘wb‘, fileobj=buffer) as f:
    f.write(uncompress_data)

# 获取压缩的数据
compress_data = buffer.getvalue()
print(‘Compressed:‘, len(compress_data))
print(‘Compress Data:‘, binascii.hexlify(compress_data))

# 重新读取数据
inbuffer = BytesIO(compress_data)
with gzip.GzipFile(mode=‘rb‘, fileobj=inbuffer) as f:
    reread_data = f.read(len(uncompress_data))
print(‘利用未压缩的长度，获取压缩后的数据长度:‘, len(reread_data))
print(reread_data)