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Diffstat (limited to 'documentation/shortintro.rst')
| -rw-r--r-- | documentation/shortintro.rst | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/documentation/shortintro.rst b/documentation/shortintro.rst index b9230e3..11b2ea0 100644 --- a/documentation/shortintro.rst +++ b/documentation/shortintro.rst @@ -53,13 +53,24 @@ Also supported with :ref:`context manager <context-manager>`:: ser.write(b'hello') +.. _shortintro_readline: + Readline ======== +:meth:`readline` reads up to one line, including the `\n` at the end. Be careful when using :meth:`readline`. Do specify a timeout when opening the serial port otherwise it could block forever if no newline character is -received. Also note that :meth:`readlines` only works with a timeout. -:meth:`readlines` depends on having a timeout and interprets that as EOF (end -of file). It raises an exception if the port is not opened correctly. +received. If the `\n` is missing in the return value, it returned on timeout. + +:meth:`readlines` tries to read "all" lines which is not well defined for a +serial port that is still open. Therefore :meth:`readlines` depends on having +a timeout on the port and interprets that as EOF (end of file). It raises an +exception if the port is not opened correctly. The returned list of lines do +not include the `\n`. + +Both functions call :meth:`read` to get their data and the serial port timeout +is acting on this function. Therefore the effective timeout, especially for +:meth:`readlines`, can be much larger. Do also have a look at the example files in the examples directory in the source distribution or online. |