StreamRecoder instances translate data from one encoding to another. They use the complete set of APIs returned by the codecs.lookup() function to implement their task. Data written to the StreamRecoder is first decoded into an intermediate format (depending
| 762 | ### |
| 763 | |
| 764 | class StreamRecoder: |
| 765 | |
| 766 | """ StreamRecoder instances translate data from one encoding to another. |
| 767 | |
| 768 | They use the complete set of APIs returned by the |
| 769 | codecs.lookup() function to implement their task. |
| 770 | |
| 771 | Data written to the StreamRecoder is first decoded into an |
| 772 | intermediate format (depending on the "decode" codec) and then |
| 773 | written to the underlying stream using an instance of the provided |
| 774 | Writer class. |
| 775 | |
| 776 | In the other direction, data is read from the underlying stream using |
| 777 | a Reader instance and then encoded and returned to the caller. |
| 778 | |
| 779 | """ |
| 780 | # Optional attributes set by the file wrappers below |
| 781 | data_encoding = 'unknown' |
| 782 | file_encoding = 'unknown' |
| 783 | |
| 784 | def __init__(self, stream, encode, decode, Reader, Writer, |
| 785 | errors='strict'): |
| 786 | |
| 787 | """ Creates a StreamRecoder instance which implements a two-way |
| 788 | conversion: encode and decode work on the frontend (the |
| 789 | data visible to .read() and .write()) while Reader and Writer |
| 790 | work on the backend (the data in stream). |
| 791 | |
| 792 | You can use these objects to do transparent |
| 793 | transcodings from e.g. latin-1 to utf-8 and back. |
| 794 | |
| 795 | stream must be a file-like object. |
| 796 | |
| 797 | encode and decode must adhere to the Codec interface; Reader and |
| 798 | Writer must be factory functions or classes providing the |
| 799 | StreamReader and StreamWriter interfaces resp. |
| 800 | |
| 801 | Error handling is done in the same way as defined for the |
| 802 | StreamWriter/Readers. |
| 803 | |
| 804 | """ |
| 805 | self.stream = stream |
| 806 | self.encode = encode |
| 807 | self.decode = decode |
| 808 | self.reader = Reader(stream, errors) |
| 809 | self.writer = Writer(stream, errors) |
| 810 | self.errors = errors |
| 811 | |
| 812 | def read(self, size=-1): |
| 813 | |
| 814 | data = self.reader.read(size) |
| 815 | data, bytesencoded = self.encode(data, self.errors) |
| 816 | return data |
| 817 | |
| 818 | def readline(self, size=None): |
| 819 | |
| 820 | if size is None: |
| 821 | data = self.reader.readline() |