Move element check out of else

Clarify reason for error and comment. The code does not need to be inside the
else statement, since the if can only raise the error.

interfaces/cython/cantera/ck2yaml.py

@@ -886,15 +886,18 @@ def read_NASA7_entry(self, lines, TintDefault, comments):
         if not composition:
             raise InputError("Error parsing elemental composition for "
                              "species '{}'", species)
-        else:
-            for symbol in composition.keys():
-
-                # check if self.parse_composition parses composition correctly
-                if any(map(str.isdigit, symbol)) and symbol not in self.elements:
-                    raise InputError("Error parsing elemental composition for "
-                                     "species thermo entry\n{}"
-                                     "\n the first line has an incorrect format", "".join(lines))
-
+
+        for symbol in composition.keys():
+            # Some CHEMKIN input files may have quantities of elements with
+            # more than 3 digits. This violates the column-based input format
+            # standard, so the entry cannot be read and we need to raise a
+            # more useful error message.
+            if any(map(str.isdigit, symbol)) and symbol not in self.elements:
+                raise InputError("Error parsing elemental composition for "
+                                 "species thermo entry:\n{}\nElement amounts"
+                                 "can have no more than 3 digits",
+                                 "".join(lines))
+
         # Extract the NASA polynomial coefficients
         # Remember that the high-T polynomial comes first!
         Tmin = fortFloat(lines[0][45:55])

test/data/big_element_num_err.inp

@@ -15,8 +15,8 @@ BIN6BJ
 END
 
 THERMO ALL
-    270.000   1000.000   3500.000 
-BIN7AJ                 C 1250H 812          G    300.00   3500.00 1260.00      1 
+    270.000   1000.000   3500.000
+BIN7AJ                 C 1250H 812          G    300.00   3500.00 1260.00      1
  2.35938249e+03 3.50442304e+00-1.25852280e-03 2.00397985e-07-1.15957197e-11    2
  2.45225502e+05-1.29759728e+04-1.05686227e+03 1.43496445e+01-1.41695007e-02    3
  7.03160324e-06-1.36699359e-09 1.10611918e+06 4.29496756e+03                   4
@@ -36,12 +36,12 @@ CO                      C   1O   1          G    200.00   3500.00  960.00      1
 -1.41723335e+04 7.41443560e+00 3.75723891e+00-2.14465241e-03 5.42079005e-06    3
 -4.17025963e-09 1.11901127e-12-1.43575530e+04 2.79976799e+00                   4
 
-BIN6AJ                  C 640H 43           G    300.00   3500.00 1290.00      1 
+BIN6AJ                  C 640H 43           G    300.00   3500.00 1290.00      1
  1.23762821e+03 1.77026241e+00-6.22545371e-04 9.54207658e-08-5.13173999e-12    2
  1.25536835e+05-6.67884001e+03-5.26755261e+02 7.24121890e+00-6.98412269e-03    3
  3.38305762e-06-6.42270665e-10 5.80747770e+05 2.28257683e+03                   4
 
-BIN6BJ                  C 640H 127          G    300.00   3500.00 1390.00      1 
+BIN6BJ                  C 640H 127          G    300.00   3500.00 1390.00      1
  1.08992363e+03 1.08035536e+00-3.02579890e-04 2.55048499e-08 8.09218683e-13    2
 -2.94595285e+05-5.83854863e+03-5.54531539e+02 5.81260044e+00-5.40931919e-03    3
  2.47478029e-06-4.39707947e-10 1.62563251e+05 2.63652221e+03                   4