[Tutor] type hint woes regex
In a first attempt to add types I ran into trouble. First a code snippet ( full code at https://gist.github.com/ingoogni/460676b11e5a04ed3a3ac93ae0e1fddd ) _matchline: Pattern[str] = re.compile(r"(?P^\s*$)|(?P[\t]*)" "((?P[A-Z]+):)?([ \t]*)(?P.*)") def proc_matchlns(momfile: TextIO) -> Iterator[Dict[str, Union[str, int]]]: for i, ln in enumerate(momfile, 1): match: Match[str] = _matchline.match(ln) #error 1 m: Dict[str, str] = match.groupdict()#error 2 m['ln'] = ln.rstrip() m['ln#'] = i #error 3 yield m #error 4 Depending on how I add types mypy nags on various aspects: error 1: match seems to want type Optional[Match[str]], but why? The regex always has a result (I hope). error 2: when I give in to the above, the result is that it errors on not being able to de a groupdict on a null type. error 3: groupdict results in a type dict[str, str], but I want to add an int. Can I change the type? (In this specific case could change i to str(i) as it has no influence on the program) error 4: result of 3 and output type, type of m and specified output type don't match. Ingo ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
[Tutor] Is this the preferred way to change terminal screen color using curses?
I wanted to be able to change the background screen color of a
terminal window using curses. My weak Google-Foo did not turn up a
clear example of how to do this despite much searching. The two
_obvious_curses methods to attempt this seemed to be
window.bkgdset(ch, attr) to initially set a window's background
attributes and window.bkgd(ch, attr) to change them to new values.
The thing that has puzzled me is that "ch" is a mandatory parameter to
supply. So after a variety of experimental efforts I came up with the
following approach which seems to do what I want to do -- just change
the terminal's background color at will. But since I did *not* locate
any clear examples online on how to do this, I cannot help but wonder
if there is an easier approach to do what I want to do?
My code follows. As always I am open to any constructive criticism
even if it is off this email's topic, though this code is not meant to
be a polished product.
#!/usr/bin/env python3
import curses
def start_cli(stdscr):
max_height, max_width = stdscr.getmaxyx()
curses.init_pair(1, curses.COLOR_BLACK, curses.COLOR_CYAN)
PAIR_BLACK_ON_CYAN = curses.color_pair(1)
stdscr.clear()
stdscr.bkgdset(' ', PAIR_BLACK_ON_CYAN)
# Fill screen with spaces to color screen background:
for y in range(max_height):
try:
stdscr.addstr(y, 0, ' ' * max_width)
except curses.error as error:
if y == max_height - 1:
# Ignore error from writing to lower right-hand screen corner:
pass
else:
raise error
# Make cursor invisible to ensure *entire* screen is colored:
curses.curs_set(0)
stdscr.refresh()
# Pause program until user presses key:
stdscr.getkey()
# Change background screen color:
curses.init_pair(2, curses.COLOR_BLACK, curses.COLOR_RED)
PAIR_BLACK_ON_RED = curses.color_pair(2)
change_bkgd_color(stdscr, PAIR_BLACK_ON_RED)
stdscr.getkey()
def change_bkgd_color(window_obj, color_pair):
window_obj.bkgd(' ', color_pair)
if __name__ == '__main__':
input("Press ENTER to change screen to first color, then press"
" any key for next color change until the program exits.")
curses.wrapper(start_cli)
--
boB
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Re: [Tutor] Is this the preferred way to change terminal screen color using curses?
On 02Mar2019 15:16, boB Stepp wrote: I wanted to be able to change the background screen color of a terminal window using curses. My weak Google-Foo did not turn up a clear example of how to do this despite much searching. The two _obvious_curses methods to attempt this seemed to be window.bkgdset(ch, attr) to initially set a window's background attributes and window.bkgd(ch, attr) to change them to new values. The thing that has puzzled me is that "ch" is a mandatory parameter to supply. Remember that the Python curses module is a shim for the curses (or ncurses) C library. So "man 3 curses" gets you the main library page, and there are distinct manual entries for the various functions. On my machine (a Mac) the curses(3) manual entry has a section named "Routine Name Index" thus: Routine Name Index The following table lists each curses routine and the name of the man‐ ual page on which it is described. Routines flagged with “*” are ncurses-specific, not described by XPG4 or present in SVr4. and then there's a long table of functions and the match manual entry name. bkgdset is listed as in the curs_bkgd(3) entry, so run "man curs_bkgd" to view that manual entry. It describes the bkgdset, wbkgdset, bkgd, wbkgd, getbkgd functions in some detail. Also, the curs_color manual entry talks about terminal colours in detail. So "man curs_color". So after a variety of experimental efforts I came up with the following approach which seems to do what I want to do -- just change the terminal's background color at will. But since I did *not* locate any clear examples online on how to do this, I cannot help but wonder if there is an easier approach to do what I want to do? I would be inclined to call getbkgd() and then modify what it gives you as desired, then call bkgdset(). Untested. My code follows. As always I am open to any constructive criticism even if it is off this email's topic, though this code is not meant to be a polished product. [...] # Fill screen with spaces to color screen background: for y in range(max_height): try: stdscr.addstr(y, 0, ' ' * max_width) except curses.error as error: if y == max_height - 1: # Ignore error from writing to lower right-hand screen corner: pass else: raise error Is the painting of the screen with spaces actually required? I would have thought not (again, untested). The main window (stdscr) should start filled with spaces. [Reads more closely...] probably you want to call bkgd() or wbkgd() instead. "man curs_bkgd" says: bkgd The bkgd and wbkgd functions set the background property of the current or specified window and then apply this setting to every character position in that window: · The rendition of every character on the screen is changed to the new background rendition. · Wherever the former background character appears, it is changed to the new background character. Cheers, Cameron Simpson ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Is this the preferred way to change terminal screen color using curses?
On Sat, Mar 2, 2019 at 4:28 PM Cameron Simpson wrote: > Is the painting of the screen with spaces actually required? I would > have thought not (again, untested). The main window (stdscr) should > start filled with spaces. I had read this along the way, but had forgotten it. > [Reads more closely...] probably you want to call bkgd() or wbkgd() > instead. "man curs_bkgd" says: > >bkgd >The bkgd and wbkgd functions set the background property of the >current or specified window and then apply this setting to every >character position in that window: >· The rendition of every character on the screen is changed to >the new background rendition. >· Wherever the former background character appears, it is changed >to the new background character. I had seen this, but I have been giving way too much credence to the names given to these methods. This is the second time I have been badly burned by the names used. I had ASSumed that if there is a bkgdset() method, that the window attributes need to be initialized first if one is not satisfied with the default behavior. And I *did* try using bkgdset() by itself without manually populating spaces, but it did not change the color of anything but the window border I had used in my original trial code. I tried your suggestion with bkgd() and it worked beautifully. BTW, my Linux Mint installation did *not* have the man pages for ncurses, even though it was installed. I had to manually fetch the man pages myself. -- boB ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] Is this the preferred way to change terminal screen color using curses?
On 02Mar2019 22:32, boB Stepp wrote: BTW, my Linux Mint installation did *not* have the man pages for ncurses, even though it was installed. I had to manually fetch the man pages myself. Maybe they're in a separate -dev or -doc package? Sometimes the base package (eg "libncurses") contains only the library, not header files or doco wanted for development. Cheers, Cameron Simpson ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
