Clarify comment about backend_pgf.writeln.

anntzer · anntzer · commit 99adcf969d81 · 2021-07-19T12:53:32.000+02:00
The need for a % is not some mysterious tex thing, but a well
documented behavior.
diff --git a/lib/matplotlib/backends/backend_pgf.py b/lib/matplotlib/backends/backend_pgf.py
@@ -116,8 +116,8 @@ def common_texification(text):
 
 
 def writeln(fh, line):
-    # every line of a file included with \\input must be terminated with %
-    # if not, latex will create additional vertical spaces for some reason
+    # Ending lines with a % prevents TeX from inserting spurious spaces
+    # (https://tex.stackexchange.com/questions/7453).
     fh.write(line)
     fh.write("%\n")
 
