Dear Maintainer,

When installing petsc, I noticed the following warnings printed:

Setting up libpetsc3.20-dev-common (3.20.6+dfsg1-3) ...
/usr/share/petsc/3.20/lib/petsc/bin/petsc_tas_analysis.py:792: SyntaxWarning: invalid escape sequence '\l'
  axMeshConv.set(xlabel='Problem Size $\log N$',
/usr/share/petsc/3.20/lib/petsc/bin/petsc_tas_analysis.py:793: SyntaxWarning: invalid escape sequence '\l'
  ylabel='Error $\log |x - x^*|$', title='Mesh Convergence')
/usr/share/petsc/3.20/lib/petsc/bin/petsclogformat.py:253: SyntaxWarning: invalid escape sequence '\d'
  print("\documentclass{article}")
/usr/share/petsc/3.20/lib/petsc/bin/petsclogformat.py:256: SyntaxWarning: invalid escape sequence '\c'
  print("\centering")
/usr/share/petsc/3.20/lib/petsc/bin/petsclogformat.py:259: SyntaxWarning: invalid escape sequence '\m'
  print(" &  & \multicolumn{4}{c}{--------------- Percent of -------------} &  \\\\")
/usr/share/petsc/3.20/lib/petsc/bin/petsclogformat.py:261: SyntaxWarning: invalid escape sequence '\h'
  print("\hline")
/usr/share/petsc/3.20/lib/petsc/bin/petsclogformat.py:321: SyntaxWarning: invalid escape sequence '\e'
  print("\end{tabular}")
/usr/share/petsc/3.20/lib/petsc/bin/petsclogformat.py:322: SyntaxWarning: invalid escape sequence '\e'
  print("\end{table}")
/usr/share/petsc/3.20/lib/petsc/bin/petsclogformat.py:323: SyntaxWarning: invalid escape sequence '\e'
  print("\end{document}")

It looks like these should perhaps be raw strings or the backslashes
should be escaped. This also makes me wonder if there might be other
cases where the use of the backslash just happened to match an actual
escape sequence and therefore would result in incorrect behaviour
without a warning.

Sincerely,
Cory Bloor