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# 文章：Python通过文件头来判断文件类型

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import struct

# 支持文件类型

# 用16进制字符串的目的是可以知道文件头是多少字节

# 各种文件头的长度不一样，少半2字符，长则8字符

#文件格式 文件头(十六进制)

#JPEG (jpg) FFD8FF

#PNG (png) 89504E47

#GIF (gif) 47494638

#TIFF (tif) 49492A00

#Windows Bitmap (bmp) 424D

#CAD (dwg) 41433130

#Adobe Photoshop (psd) 38425053

#Rich Text Format (rtf) 7B5C727466

#XML (xml) 3C3F786D6C

#HTML (html) 68746D6C3E

#Email [thorough only] (eml) 44656C69766572792D646174653A

#Outlook Express (dbx) CFAD12FEC5FD746F

#Outlook (pst) 2142444E

#MS Word/Excel (xls.or.doc) D0CF11E0

#MS Access (mdb) 5374616E64617264204A

#WordPerfect (wpd) FF575043

#Postscript (eps.or.ps) 252150532D41646F6265

#Adobe Acrobat (pdf) 255044462D312E

#Quicken (qdf) AC9EBD8F

#Windows Password (pwl) E3828596

#ZIP Archive (zip) 504B0304

#RAR Archive (rar) 52617221

#Wave (wav) 57415645

#AVI (avi) 41564920

#Real Audio (ram) 2E7261FD

#Real Media (rm) 2E524D46

#MPEG (mpg) 000001BA

#MPEG (mpg) 000001B3

#Quicktime (mov) 6D6F6F76

#Windows Media (asf) 3026B2758E66CF11

#MIDI (mid) 4D546864

def typeList():

return {

"52617221": EXT_RAR,

"504B0304": EXT_ZIP

}

#end typeList

# 字节码转16进制字符串

def bytes2hex(bytes):

num = len(bytes)

hexstr = u""

for i in range(num):

t = u"%x" % bytes[i]

if len(t) % 2:

hexstr += u"0"

hexstr += t

return hexstr.upper()

#end bytes2hex

# 获取文件类型

def filetype(filename):

binfile = open(filename, 'rb') # 必需二制字读取

tl = typeList()

ftype = 'unknown'

for hcode in tl.keys():

numOfBytes = len(hcode) / 2 # 需要读多少字节

binfile.seek(0) # 每次读取都要回到文件头，不然会一直往后读取

hbytes = struct.unpack_from("B"*numOfBytes, binfile.read(numOfBytes)) # 一个 "B"表示一个字节

f_hcode = bytes2hex(hbytes)

if f_hcode == hcode:

ftype = tl[hcode]

break

binfile.close()

return ftype

#end filetype

if __name__ == '__main__':

filePath = ""

print filetype(filePath)

# http://ju.outofmemory.cn/entry/45562

# http://blog.csdn.net/shuifa2008/article/details/9333193