"Read and write ZIP files"
# Written by James C. Ahlstrom jim@interet.com
# All rights transferred to CNRI pursuant to the Python contribution agreement
import struct, os, time
import binascii, py_compile
try:
import zlib # We may need its compression method
try:
binascii.crc32
except AttributeError:
binascii.crc32 = zlib.crc32
except:
zlib = None
class _BadZipfile(Exception):
pass
error = _BadZipfile # The exception raised by this module
# constants for Zip file compression methods
ZIP_STORED = 0
ZIP_DEFLATED = 8
# Other ZIP compression methods not supported
# Here are some struct module formats for reading headers
structEndArchive = "<4s4H2lH" # 9 items, end of archive, 22 bytes
stringEndArchive = "PK\005\006" # magic number for end of archive record
structCentralDir = "<4s4B4H3l5H2l"# 19 items, central directory, 46 bytes
stringCentralDir = "PK\001\002" # magic number for central directory
structFileHeader = "<4s2B4H3l2H" # 12 items, file header record, 30 bytes
stringFileHeader = "PK\003\004" # magic number for file header
def is_zipfile(filename):
"""Quickly see if file is a ZIP file by checking the magic number.
Will not accept a ZIP archive with an ending comment."""
try:
fpin = open(filename, "rb")
fpin.seek(-22, 2) # Seek to end-of-file record
endrec = fpin.read()
fpin.close()
if endrec[0:4] == "PK\005\006" and endrec[-2:] == "\000\000":
return 1 # file has correct magic number
except:
pass
class ZipInfo:
"Class with attributes describing each file in the ZIP archive"
def __init__(self, filename="NoName", date_time=(1980,1,1,0,0,0)):
self.filename = filename # Name of the file in the archive
self.date_time = date_time # year, month, day, hour, min, sec
# Standard values:
self.compress_type = ZIP_STORED # Type of compression for the file
self.comment = "" # Comment for each file
self.extra = "" # ZIP extra data
self.create_system = 0 # System which created ZIP archive
self.create_version = 20 # Version which created ZIP archive
self.extract_version = 20 # Version needed to extract archive
self.reserved = 0 # Must be zero
self.flag_bits = 0 # ZIP flag bits
self.volume = 0 # Volume number of file header
self.internal_attr = 0 # Internal attributes
self.external_attr = 0 # External file attributes
# Other attributes are set by class ZipFile:
# header_offset Byte offset to the file header
# file_offset Byte offset to the start of the file data
# CRC CRC-32 of the uncompressed file
# compress_size Size of the compressed file
# file_size Size of the uncompressed file
def FileHeader(self):
'Return the per-file header as a string'
dt = self.date_time
dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
dostime = dt[3] << 11 | dt[4] << 5 | dt[5] / 2
if self.flag_bits & 0x08:
# Set these to zero because we write them after the file data
CRC = compress_size = file_size = 0
else:
CRC = self.CRC
compress_size = self.compress_size
file_size = self.file_size
header = struct.pack(structFileHeader, stringFileHeader,
self.extract_version, self.reserved, self.flag_bits,
self.compress_type, dostime, dosdate, CRC,
compress_size, file_size,
len(self.filename), len(self.extra))
return header + self.filename + self.extra
class ZipFile:
"Class with methods to open, read, write, close, list zip files"
def __init__(self, filename, mode="r", compression=ZIP_STORED):
'Open the ZIP file with mode read "r", write "w" or append "a".'
if compression == ZIP_STORED:
pass
elif compression == ZIP_DEFLATED:
if not zlib:
raise RuntimeError,\
"Compression requires the (missing) zlib module"
else:
raise RuntimeError, "That compression method is not supported"
self.debug = 0 # Level of printing: 0 through 3
self.NameToInfo = {} # Find file info given name
self.filelist = [] # List of ZipInfo instances for archive
self.compression = compression # Method of compression
self.filename = filename
self.mode = key = mode[0]
if key == 'r':
self.fp = open(filename, "rb")
self._GetContents()
elif key == 'w':
self.fp = open(filename, "wb")
elif key == 'a':
fp = self.fp = open(filename, "r+b")
fp.seek(-22, 2) # Seek to end-of-file record
endrec = fp.read()
if endrec[0:4] == stringEndArchive and \
endrec[-2:] == "\000\000":
self._GetContents() # file is a zip file
# seek to start of directory and overwrite
fp.seek(self.start_dir, 0)
else: # file is not a zip file, just append
fp.seek(0, 2)
else:
raise RuntimeError, 'Mode must be "r", "w" or "a"'
def _GetContents(self):
"Read in the table of contents for the zip file"
fp = self.fp
fp.seek(-22, 2) # Start of end-of-archive record
filesize = fp.tell() + 22 # Get file size
endrec = fp.read(22) # Archive must not end with a comment!
if endrec[0:4] != stringEndArchive or endrec[-2:] != "\000\000":
raise error, "File is not a zip file, or ends with a comment"
endrec = struct.unpack(structEndArchive, endrec)
if self.debug > 1:
print endrec
size_cd = endrec[5] # bytes in central directory
offset_cd = endrec[6] # offset of central directory
x = filesize - 22 - size_cd
# "concat" is zero, unless zip was concatenated to another file
concat = x - offset_cd
if self.debug > 2:
print "given, inferred, offset", offset_cd, x, concat
# self.start_dir: Position of start of central directory
self.start_dir = offset_cd + concat
fp.seek(self.start_dir, 0)
total = 0
while total < size_cd:
centdir = fp.read(46)
total = total + 46
if centdir[0:4] != stringCentralDir:
raise error, "Bad magic number for central directory"
centdir = struct.unpack(structCentralDir, centdir)
if self.debug > 2:
print centdir
filename = fp.read(centdir[12])
# Create ZipInfo instance to store file information
x = ZipInfo(filename)
x.extra = fp.read(centdir[13])
x.comment = fp.read(centdir[14])
total = total + centdir[12] + centdir[13] + centdir[14]
x.header_offset = centdir[18] + concat
x.file_offset = x.header_offset + 30 + centdir[12] + centdir[13]
(x.create_version, x.create_system, x.extract_version, x.reserved,
x.flag_bits, x.compress_type, t, d,
x.CRC, x.compress_size, x.file_size) = centdir[1:12]
x.volume, x.internal_attr, x.external_attr = centdir[15:18]
# Convert date/time code to (year, month, day, hour, min, sec)
x.date_time = ( (d>>9)+1980, (d>>5)&0xF, d&0x1F,
t>>11, (t>>5)&0x3F, (t&0x1F) * 2 )
self.filelist.append(x)
self.NameToInfo[x.filename] = x
if self.debug > 2:
print "total", total
for data in self.filelist:
fp.seek(data.header_offset, 0)
fheader = fp.read(30)
if fheader[0:4] != stringFileHeader:
raise error, "Bad magic number for file header"
fheader = struct.unpack(structFileHeader, fheader)
fname = fp.read(fheader[10])
if fname != data.filename:
raise RuntimeError, \
'File name in Central Directory "%s" and File Header "%s" differ.' % (
data.filename, fname)
def namelist(self):
"Return a list of file names in the archive"
l = []
for data in self.filelist:
l.append(data.filename)
return l
def infolist(self):
"Return a list of class ZipInfo instances for files in the archive"
return self.filelist
def printdir(self):
"Print a table of contents for the zip file"
print "%-46s %19s %12s" % ("File Name", "Modified ", "Size")
for zinfo in self.filelist:
date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time
print "%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size)
def testzip(self):
"Read all the files and check the CRC"
for zinfo in self.filelist:
try:
self.read(zinfo.filename) # Check CRC-32
except:
return zinfo.filename
def getinfo(self, name):
'Return the instance of ZipInfo given "name"'
return self.NameToInfo[name]
def read(self, name):
"Return file bytes (as a string) for name"
if self.mode not in ("r", "a"):
raise RuntimeError, 'read() requires mode "r" or "a"'
if not self.fp:
raise RuntimeError, \
"Attempt to read ZIP archive that was already closed"
zinfo = self.getinfo(name)
filepos = self.fp.tell()
self.fp.seek(zinfo.file_offset, 0)
bytes = self.fp.read(zinfo.compress_size)
self.fp.seek(filepos, 0)
if zinfo.compress_type == ZIP_STORED:
pass
elif zinfo.compress_type == ZIP_DEFLATED:
if not zlib:
raise RuntimeError, \
"De-compression requires the (missing) zlib module"
# zlib compress/decompress code by Jeremy Hylton of CNRI
dc = zlib.decompressobj(-15)
bytes = dc.decompress(bytes)
# need to feed in unused pad byte so that zlib won't choke
ex = dc.decompress('Z') + dc.flush()
if ex:
bytes = bytes + ex
else:
raise error, \
"Unsupported compression method %d for file %s" % \
(zinfo.compress_type, name)
crc = binascii.crc32(bytes)
if crc != zinfo.CRC:
raise error, "Bad CRC-32 for file %s" % name
return bytes
def _writecheck(self, zinfo):
'Check for errors before writing a file to the archive'
if self.NameToInfo.has_key(zinfo.filename):
if self.debug: # Warning for duplicate names
print "Duplicate name:", zinfo.filename
if self.mode not in ("w", "a"):
raise RuntimeError, 'write() requires mode "w" or "a"'
if not self.fp:
raise RuntimeError, \
"Attempt to write ZIP archive that was already closed"
if zinfo.compress_type == ZIP_DEFLATED and not zlib:
raise RuntimeError, \
"Compression requires the (missing) zlib module"
if zinfo.compress_type not in (ZIP_STORED, ZIP_DEFLATED):
raise RuntimeError, \
"That compression method is not supported"
def write(self, filename, arcname=None, compress_type=None):
'Put the bytes from filename into the archive under the name arcname.'
st = os.stat(filename)
mtime = time.localtime(st[8])
date_time = mtime[0:6]
# Create ZipInfo instance to store file information
if arcname is None:
zinfo = ZipInfo(filename, date_time)
else:
zinfo = ZipInfo(arcname, date_time)
zinfo.external_attr = st[0] << 16 # Unix attributes
if compress_type is None:
zinfo.compress_type = self.compression
else:
zinfo.compress_type = compress_type
self._writecheck(zinfo)
fp = open(filename, "rb")
zinfo.flag_bits = 0x08
zinfo.header_offset = self.fp.tell() # Start of header bytes
self.fp.write(zinfo.FileHeader())
zinfo.file_offset = self.fp.tell() # Start of file bytes
CRC = 0
compress_size = 0
file_size = 0
if zinfo.compress_type == ZIP_DEFLATED:
cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
zlib.DEFLATED, -15)
else:
cmpr = None
while 1:
buf = fp.read(1024 * 8)
if not buf:
break
file_size = file_size + len(buf)
CRC = binascii.crc32(buf, CRC)
if cmpr:
buf = cmpr.compress(buf)
compress_size = compress_size + len(buf)
self.fp.write(buf)
fp.close()
if cmpr:
buf = cmpr.flush()
compress_size = compress_size + len(buf)
self.fp.write(buf)
zinfo.compress_size = compress_size
else:
zinfo.compress_size = file_size
zinfo.CRC = CRC
zinfo.file_size = file_size
# Write CRC and file sizes after the file data
self.fp.write(struct.pack("<lll", zinfo.CRC, zinfo.compress_size,
zinfo.file_size))
self.filelist.append(zinfo)
self.NameToInfo[zinfo.filename] = zinfo
def writestr(self, zinfo, bytes):
'Write a file into the archive. The contents is the string "bytes"'
self._writecheck(zinfo)
zinfo.file_size = len(bytes) # Uncompressed size
zinfo.CRC = binascii.crc32(bytes) # CRC-32 checksum
if zinfo.compress_type == ZIP_DEFLATED:
co = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
zlib.DEFLATED, -15)
bytes = co.compress(bytes) + co.flush()
zinfo.compress_size = len(bytes) # Compressed size
else:
zinfo.compress_size = zinfo.file_size
zinfo.header_offset = self.fp.tell() # Start of header bytes
self.fp.write(zinfo.FileHeader())
zinfo.file_offset = self.fp.tell() # Start of file bytes
self.fp.write(bytes)
if zinfo.flag_bits & 0x08:
# Write CRC and file sizes after the file data
self.fp.write(struct.pack("<lll", zinfo.CRC, zinfo.compress_size,
zinfo.file_size))
self.filelist.append(zinfo)
self.NameToInfo[zinfo.filename] = zinfo
def __del__(self):
'Call the "close()" method in case the user forgot'
if self.fp:
self.fp.close()
self.fp = None
def close(self):
'Close the file, and for mode "w" and "a" write the ending records'
if self.mode in ("w", "a"): # write ending records
count = 0
pos1 = self.fp.tell()
for zinfo in self.filelist: # write central directory
count = count + 1
dt = zinfo.date_time
dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
dostime = dt[3] << 11 | dt[4] << 5 | dt[5] / 2
centdir = struct.pack(structCentralDir,
stringCentralDir, zinfo.create_version,
zinfo.create_system, zinfo.extract_version, zinfo.reserved,
zinfo.flag_bits, zinfo.compress_type, dostime, dosdate,
zinfo.CRC, zinfo.compress_size, zinfo.file_size,
len(zinfo.filename), len(zinfo.extra), len(zinfo.comment),
0, zinfo.internal_attr, zinfo.external_attr,
zinfo.header_offset)
self.fp.write(centdir)
self.fp.write(zinfo.filename)
self.fp.write(zinfo.extra)
self.fp.write(zinfo.comment)
pos2 = self.fp.tell()
# Write end-of-zip-archive record
endrec = struct.pack(structEndArchive, stringEndArchive,
0, 0, count, count, pos2 - pos1, pos1, 0)
self.fp.write(endrec)
self.fp.close()
self.fp = None
class PyZipFile(ZipFile):
"Class to create ZIP archives with Python library files and packages"
def writepy(self, pathname, basename = ""):
"""Add all files from "pathname" to the ZIP archive.
If pathname is a package directory, search the directory and all
package subdirectories recursively for all *.py and enter the modules into
the archive. If pathname is a plain directory, listdir *.py and enter all
modules. Else, pathname must be a Python *.py file and the module will be
put into the archive. Added modules are always module.pyo or module.pyc.
This method will compile the module.py into module.pyc if necessary."""
dir, name = os.path.split(pathname)
if os.path.isdir(pathname):
initname = os.path.join(pathname, "__init__.py")
if os.path.isfile(initname):
# This is a package directory, add it
if basename:
basename = "%s/%s" % (basename, name)
else:
basename = name
if self.debug:
print "Adding package in", pathname, "as", basename
fname, arcname = self._get_codename(initname[0:-3], basename)
if self.debug:
print "Adding", arcname
self.write(fname, arcname)
dirlist = os.listdir(pathname)
dirlist.remove("__init__.py")
# Add all *.py files and package subdirectories
for filename in dirlist:
path = os.path.join(pathname, filename)
root, ext = os.path.splitext(filename)
if os.path.isdir(path):
if os.path.isfile(os.path.join(path, "__init__.py")):
# This is a package directory, add it
self.writepy(path, basename) # Recursive call
elif ext == ".py":
fname, arcname = self._get_codename(path[0:-3],
basename)
if self.debug:
print "Adding", arcname
self.write(fname, arcname)
else:
# This is NOT a package directory, add its files at top level
if self.debug:
print "Adding files from directory", pathname
for filename in os.listdir(pathname):
path = os.path.join(pathname, filename)
root, ext = os.path.splitext(filename)
if ext == ".py":
fname, arcname = self._get_codename(path[0:-3],
basename)
if self.debug:
print "Adding", arcname
self.write(fname, arcname)
else:
if pathname[-3:] != ".py":
raise RuntimeError, \
'Files added with writepy() must end with ".py"'
fname, arcname = self._get_codename(pathname[0:-3], basename)
if self.debug:
print "Adding file", arcname
self.write(fname, arcname)
def _get_codename(self, pathname, basename):
"""Return (filename, archivename) for the path.
Given a module name path, return the correct file path and archive name,
compiling if necessary. For example, given /python/lib/string,
return (/python/lib/string.pyc, string)"""
file_py = pathname + ".py"
file_pyc = pathname + ".pyc"
file_pyo = pathname + ".pyo"
if os.path.isfile(file_pyo) and \
os.stat(file_pyo)[8] >= os.stat(file_py)[8]:
fname = file_pyo # Use .pyo file
elif not os.path.isfile(file_pyc) or \
os.stat(file_pyc)[8] < os.stat(file_py)[8]:
if self.debug:
print "Compiling", file_py
py_compile.compile(file_py, file_pyc)
fname = file_pyc
else:
fname = file_pyc
archivename = os.path.split(fname)[1]
if basename:
archivename = "%s/%s" % (basename, archivename)
return (fname, archivename)
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