Pygments piped to less inside python script breaks highlighting

Question

from pygments.lexers import RstLexer
from pygments.formatters import TerminalFormatter
from pygments import highlight

output = highlight(source, RstLexer(), TerminalFormatter())

p = subprocess.Popen('less', stdin=subprocess.PIPE)
p.stdin.write(output)
p.stdin.close()
p.wait()

When I just print output - everything is ok, but piping breaks highlighting… Any ideas?

example:

Answer 1

That's less's fault, not Python's. Run less with the -R switch:

-R or --RAW-CONTROL-CHARS

Like -r, but only ANSI "color" escape sequences are output in "raw" form. Unlike -r, the screen appearance is maintained correctly in most cases. ANSI "color" escape sequences are sequences of the form:

ESC [ ... m

where the "..." is zero or more color specification characters For the purpose of keeping track of screen appearance, ANSI color escape sequences are assumed to not move the cursor. You can make less think that characters other than "m" can end ANSI color escape sequences by setting the environment variable LESSANSIENDCHARS to the list of characters which can end a color escape sequence. And you can make less think that characters other than the standard ones may appear between the ESC and the m by setting the environment variable LESSANSIMIDCHARS to the list of characters which can appear.