check file containing chinese,but not in utf-8 format

check_utf8.py

#coding:utf-8

suffix_list = ['.cpp','.c','.h','.hpp','.txt','.html','.htm','.xml','.py']

def FoundInvalidFile(input_folder):#str,list
    def calc_bom(str1):
        rt = ''
        for i in range(0,3):
            rt += '%02X'%(ord(str1[i]))
        return rt
    def walk(str1):
        import os,os.path
        str1 = os.path.abspath(str1)
        for file in [file for file in os.listdir(str1) if not file in [".",".."]]:
            nfile = os.path.join(str1,file)
            if os.path.isdir(nfile) is True:
                walk(nfile)
                pass
            else:
                nfile = nfile.replace('\\','/')
                file_suffix = None
                for each in suffix_list:
                    if nfile.lower().endswith(each) is True:
                        file_suffix = each
                        break
                if file_suffix is None:
                    continue
                #file1 = nfile.replace(input_folder + '/','',1)
                #print file1
                f1 = open(nfile,'rb')
                s1 = f1.read()
                try:
                    if len(s1) > 3:
                        if 'EFBBBF' == calc_bom(s1[0:4]):
                            s1[3:].decode('utf-8')
                            continue
                    s1.decode('utf-8')
                except Exception,e:
                    print nfile,str(e)
    walk(input_folder)
    
if __name__ == "__main__":
    FoundInvalidFile('.')