Yes I'm sure. From the link Thomas sent, Any property specification, unless it is postfixed with a `+`, will *reset* the value of that property to its current value.
C-c C-v <TAB> (for me, Charles uses C-c C-v C-i) withitn a code block shows you the header args that are set for that block. Useful for debugging. -k. On Mon, Mar 30, 2020 at 3:24 PM Joost Kremers <joostkrem...@fastmail.fm> wrote: > > On Mon, Mar 30 2020, Ken Mankoff wrote: > > Header args overwrite. Change python to python+ to append header > > args. > > Are you sure? That's not documented anywhere I can find and it > seems to be belied by the fact that if I put the headers in the > order: > > ``` > :PROPERTIES: > :header-args:python: :tangle out1.py > :header-args:python: :session py1 :results function > :END: > ``` > > everything works as I would expect (the code blocks are tangled to > a file `out1.py` *and* they are evaluated in a python session > `py1`), meaning that *all* header args are picked up. > > If I reverse the order and add a `+` sign, like so: > > ``` > :PROPERTIES: > :header-args:python+: :session py1 :results function > :header-args:python+: :tangle out1.py > :END: > ``` > > the code does indeed get tangled, but the `:results` header arg > isn't picked up, because the code block doesn't produce any > output. > > For reference, this is my test file: > > ``` > * Header 1 > :PROPERTIES: > :header-args:python+: :session py1 :results function > :header-args:python+: :tangle out1.py > :END: > > #+begin_src python > a=1 > b=2 > c=a+b > return c > #+end_src > > #+RESULTS: > ``` > > > -- > Joost Kremers > Life has its moments >
