python unicode str conversion functions

strutils.py

# -*- coding: utf-8 -*-
"""
Created on 2017/5/25

@author: itakura

"Unicode <-> str 変換関連"
"""
class strutils:
    
    @staticmethod
    def force_to_str(src, none_to_empty = True):
        """
        str, unicode, None, List, tuple, object などをとにかく str にする
        :param src: もとの Object
        :param none_to_empty: True の場合、None は空文字に変換, False の場合 "None"
        :return: str
        """
        if src is None:
            if none_to_empty:
                return ""
            else:
                return "None"
        if isinstance(src, str):
            return src
        if isinstance(src, unicode):
            return src.encode('utf-8')
        if isinstance(src, tuple):
            strlist =  [strutils.force_to_str(s, none_to_empty) for s in src]
            return "(" + ",".join(strlist) + ")"
        if isinstance(src, list):
            strlist =  [strutils.force_to_str(s, none_to_empty) for s in src]
            return "[" + ",".join(strlist) + "]"
        ## just try to apply str() for any other object
        try:
            return(str(src))
        except Exception, e:
            return str(e)

    @staticmethod
    def force_to_unicode(src, none_to_empty = True):
        """
        str, unicode, None, List, tuple, object などをとにかく unicode にする
        :param src: もとの Object
        :param none_to_empty: True の場合、None は空文字に変換, False の場合 "None"
        :return: unicode。src が List や tuple だった場合、unicode の List
        """
        if src is None:
            if none_to_empty:
                return u""
            else:
                return u"None"
        if isinstance(src, str):
            return unicode(src, 'utf-8')
        if isinstance(src, unicode):
            return src
        if isinstance(src, tuple):
            unicodelist =  [strutils.force_to_unicode(s, none_to_empty) for s in src]
            return u"(" + u",".join(unicodelist) + u")"
        if isinstance(src, list):
            unicodelist =  [strutils.force_to_unicode(s, none_to_empty) for s in src]
            return u"[" + u",".join(unicodelist) + u"]"
        ## just try to apply str() for any other object
        try:
            return(unicode(str(src), 'utf-8'))
        except Exception, e:
            return unicode(str(e), 'utf-8')

    @staticmethod
    def force_to_str_list(srclist, none_to_empty = True, flatten = False):
        """
        List, tuple に含まれる内容を str にして list にする

        :param src: もとの Object
        :param none_to_empty: True の場合、None は空文字に変換, False の場合 "None"
        :param flatten: True の場合 flat にする
        :return: str
        """
        result = []
        for src in srclist:
            if isinstance(src, tuple) or isinstance(src, list):
                rlist = strutils.force_to_str_list(src, none_to_empty, flatten)
                if flatten:
                    result.extend(rlist)
                else:
                    result.append(rlist)
            else:
                result.append(strutils.force_to_str(src, none_to_empty))
        return result

    @staticmethod
    def force_to_unicode_list(srclist, none_to_empty = True, flatten = False):
        """
        List, tuple に含まれる内容を unicode にして list にする

        :param src: もとの Object
        :param none_to_empty: True の場合、None は空文字に変換, False の場合 "None"
        :param flatten: True の場合 flat にする
        :return: str
        """
        result = []
        for src in srclist:
            if isinstance(src, tuple) or isinstance(src, list):
                rlist = strutils.force_to_unicode_list(src, none_to_empty, flatten)
                if flatten:
                    result.extend(rlist)
                else:
                    result.append(rlist)
            else:
                result.append(strutils.force_to_unicode(src, none_to_empty))
        return result


    @staticmethod
    def force_print(src, none_to_empty = True):
        """
        str, unicode, None, List, tuple, object などをとにかく 文字列にして print する
        :param src:
        :param none_to_empty:
        :return:
        """
        print strutils.force_to_str(src, none_to_empty)