Python 判断文件编码

Question

import chardet
import config
from chardet.universaldetector import UniversalDetector
"""性能比较差"""
def detectFile(file_name):
    detector = UniversalDetector()
    file_obj = open(file_name)
    for line in file_obj.readlines():
        # 分块进行测试，直到达到阈值
        detector.feed(line)
        if detector.done: break
    # 关闭检测对象
    detector.close()
    file_obj.close()
    # 输出检测结果
    if not detector.result.has_key("encoding"):
        detector.result["encoding"] = config.DEFAULT_ENCODING
    if str.lower(str(detector.result["encoding"])) == "gb2312":
        detector.result["encoding"] = "gbk"
    if str.lower(str(detector.result["encoding"])).startswith("asc"):
        detector.result["encoding"] = "utf8"
    return detector.result

def detectUTF8(file_name):
    isutf8 = True
    line_num = 0
    state = 0
    file_obj = open(file_name)
    all_lines = file_obj.readlines()
    file_obj.close()
    for line in all_lines:
        line_num += 1
        line_len = len(line)
        for index in range(line_len):
            if state == 0:
                if ord(line[index])&0x80 == 0x00:
                    state = 0
                elif ord(line[index])&0xE0 == 0xC0:
                    state = 1
                elif ord(line[index])&0xF0 == 0xE0:
                    state = 2
                elif ord(line[index])&0xF8 == 0xF0:
                    state = 3
                else:
                    isutf8 = False
                    break
            else:
                if not ord(line[index])&0xC0 == 0x80:
                    isutf8 = False
                    break
                state -= 1
        if not isutf8:
            break
    return isutf8


def detectFile2(full_path)
            encoding_type = get_encoding_type_of_file(full_path)
            with codecs.open(full_path, 'r', encoding_type) as file_handler:
                self.FileBuffer = file_handler.read()
                file_handler.seek(0)
                self.FileLinesBuffer = file_handler.readlines()
def get_encoding_type_of_file(full_path):
    with open(full_path, 'r') as file_handler:
        file_content = file_handler.read()
        encoding_type = chardet.detect(file_content).get("encoding")
        return encoding_type if encoding_type.lower() != 'gb2312' else 'gbk'