Update pycbc/types/optparse.py

Co-authored-by: Tito Dal Canton <[email protected]>

pycbc/types/optparse.py

@@ -545,11 +545,14 @@ def angle_as_radians(s):
     (e.g. 12deg, 1rad), "<value> <unit>" (e.g. 12 deg, 1 rad) or just
     "<value>", in which case the unit will be assumed to be radians.
 
-    When writing angles in configuration files as options to be passed to
-    executables that rely on this function and require angles in their command
-    line, the format "<value> <unit>", with the quotation marks included,
-    prevents errors with negative values due to how Pegasus renders options in
-    .sh files.
+    Note that the format "<value><unit>", with a negative value and no space,
+    is not parsed correctly by argparse; for more information, see
+    https://stackoverflow.com/questions/16174992/cant-get-argparse-to-read-quoted-string-with-dashes-in-it
+
+    Note: when writing angles in workflow configuration files as options to be
+    passed to executables that rely on this function and require angles in their
+    command line, the format "<value> <unit>", with the quotation marks
+    included, is required due to how Pegasus renders options in .sh files.
 
     To be used as type in argparse arguments.
     """