pylint fixes

gpkit/tools/docstring.py

@@ -7,15 +7,15 @@
 
 def expected_unbounded(instance, doc):
     "Gets expected-unbounded variables from a string"
-    # pylint: disable=too-many-locals,too-many-nested-blocks
+    # pylint: disable=too-many-locals,too-many-nested-blocks,too-many-branches
     exp_unbounded = set()
     for direction in ["upper", "lower"]:
         flag = direction[0].upper()+direction[1:]+" Unbounded\n"
         count = doc.count(flag)
         if count == 0:
             continue
         if count > 1:
-            raise ValueError("multiple instances of %s" % flag)
+            raise ValueError(f"multiple instances of {flag}")
 
         idx = doc.index(flag) + len(flag)
         idx2 = doc[idx:].index("\n")
@@ -44,11 +44,11 @@ def expected_unbounded(instance, doc):
                     for subdot in var.split("."):
                         obj = getattr(obj, subdot)
                     variables = obj
-                except AttributeError:
-                    raise AttributeError("`%s` is noted in %s as "
-                                         "unbounded, but is not "
-                                         "an attribute of that model."
-                                         % (var, instance.__class__.__name__))
+                except AttributeError as err:
+                    raise AttributeError(
+                        f"`{var}` is noted in {instance.__class__.__name__} as"
+                        " unbounded, but is not an attribute of that model."
+                        ) from err
                 if not hasattr(variables, "shape"):
                     variables = np.array([variables])
                 it = np.nditer(variables, flags=['multi_index', 'refs_ok'])
@@ -59,7 +59,7 @@ def expected_unbounded(instance, doc):
     return exp_unbounded
 
 
-class parse_variables:  # pylint:disable=invalid-name
+class parse_variables:  # pylint:disable=invalid-name,too-few-public-methods
     """decorator for adding local Variables from a string.
 
     Generally called as `@parse_variables(__doc__, globals())`.
@@ -119,15 +119,16 @@ def parse_varstring(string):
     # imports, to be updated if more things are parsed above
     out[0] = "from gpkit import Variable, VectorVariable" + "  " + out[0]
     for lines, indexs in (consts, variables, vecvars):
+        # pylint: disable=no-member  # for lines.split()
         for line, index in zip(lines.split("\n"), indexs):
-            out[index] = line + "  # from '%s'" % out[index][1:].strip()
+            out[index] = line + f"  # from '{out[index][1:].strip()}'"
     return "\n".join(out)
 
 
 def vv_declare(string, flag, idx2, countstr):
     "Turns Variable declarations into VectorVariable ones"
     length = string[len(flag):idx2].strip()
-    return countstr.replace("Variable(", "VectorVariable(%s, " % length)
+    return countstr.replace("Variable(", f"VectorVariable({length}, ")
 
 
 # pylint: disable=unused-argument
@@ -157,10 +158,10 @@ def check_and_parse_flag(string, flag, declaration_func=None):
                 break
             try:
                 units = line[line.index("[")+1:line.index("]")]
-            except ValueError:
+            except ValueError as err:
                 raise ValueError("A unit declaration bracketed by [] was"
                                  " not found on the line reading:\n"
-                                 "    %s" % line)
+                                 f"    {line}") from err
             nameval = line[:line.index("[")].split()
             labelstart = line.index("]") + 1
             if labelstart >= len(line):
@@ -188,14 +189,13 @@ def check_and_parse_flag(string, flag, declaration_func=None):
 def variable_declaration(nameval, units, label, line, errorcatch=True):
     "Turns parsed output into a Variable declaration"
     if len(nameval) > 2:
-        raise ValueError("while parsing the line '%s', additional fields"
+        raise ValueError(f"while parsing the line '{line}', additional fields"
                          " (separated by whitespace) were found between Value"
-                         " '%s' and the Units `%s`. %s"
-                         % (line, nameval[1], units, PARSETIP))
+                         f" '{nameval[1]}' and the Units `{units}`. {PARSETIP}")
     if len(nameval) == 2:
-        out = ("{0} = self.{0} = Variable('{0}', {1}, '{2}', '{3}')")
+        out = "{0} = self.{0} = Variable('{0}', {1}, '{2}', '{3}')"
         out = out.format(nameval[0], nameval[1], units, label)
     elif len(nameval) == 1:
-        out = ("{0} = self.{0} = Variable('{0}', '{1}', '{2}')")
+        out = "{0} = self.{0} = Variable('{0}', '{1}', '{2}')"
         out = out.format(nameval[0], units, label)
     return out + "\n"