dimensionless

pint/delegates/formatter/_compound_unit_helpers.py

@@ -254,7 +254,9 @@ def prepare_compount_unit(
         out = unit._units.items()
     else:
         out = unit
-
+    print(out)
+    if len(out) == 0 and not "~" in spec:
+        out = {"dimensionless": 1}.items()
     # out: unit_name, unit_exponent
 
     if "~" in spec:

pint/delegates/formatter/_format_helpers.py

@@ -131,6 +131,8 @@ def join_mu(joint_fstring: str, mstr: str, ustr: str) -> str:
 
     This avoids that `3 and `1 / m` becomes `3 1 / m`
     """
+    if ustr == "":
+        return mstr
     if ustr.startswith("1 / "):
         return joint_fstring.format(mstr, ustr[2:])
     return joint_fstring.format(mstr, ustr)
@@ -211,7 +213,7 @@ def formatter(
             neg_terms.append(power_fmt.format(key, fun(value)))
 
     if not pos_terms and not neg_terms:
-        return "dimensionless"
+        return ""
 
     if not as_ratio:
         # Show as Product: positive * negative terms ** -1

pint/testsuite/test_issues.py

@@ -1264,5 +1264,6 @@ def test_issue2007():
     assert f"{q:C}" == '1 dimensionless'
     assert f"{q:D}" == '1 dimensionless'
     assert f"{q:H}" == '1 dimensionless'
-    assert f"{q:L}" == '1\\ dimensionless'
-    assert f"{q:Lx}" == '\\SI[]{1}{}'
+    # assert f"{q:L}" == '1\\ dimensionless'
+    assert f"{q:Lx}" == '\\SI[]{1}{}'
+    assert f"{q:~P}" == '1'