Update chemicalFormulas.py example to use new runTests postParse argument, add test cases that parse subscript integers

2 files changed, 49 insertions, 28 deletions

diff --git a/CHANGES b/CHANGES
index c4b95a2..93f66d5 100644
--- a/CHANGES
+++ b/CHANGES
@@ -35,7 +35,7 @@ Version 2.3.1 -
 - Added optional postParse argument to ParserElement.runTests() to add a
   custom callback to be called for test strings that parse successfully. Useful
   for running tests that do additional validation or processing on the parsed
-  results.
+  results. See updated chemcialFormulas.py example.
 
 - Removed distutils fallback in setup.py. If installing the package fails,
   please update to the latest version of setuptools. Plus overall project code
diff --git a/examples/chemicalFormulas.py b/examples/chemicalFormulas.py
index 31d77de..abbe332 100644
--- a/examples/chemicalFormulas.py
+++ b/examples/chemicalFormulas.py
@@ -1,3 +1,5 @@
+# -*- coding: utf-8 -*-

+#

 # chemicalFormulas.py

 #

 # Copyright (c) 2003, Paul McGuire

@@ -11,46 +13,41 @@ atomicWeight = {
     "H"  : 1.00794,

     "Na" : 22.9897,

     "Cl" : 35.4527,

-    "C"  : 12.0107

+    "C"  : 12.0107,

     }

 

-def test( bnf, strg, fn=None ):

-    try:

-        print(strg,"->", bnf.parseString( strg ), end=' ')

-    except ParseException as pe:

-        print(pe)

-    else:

-        if fn != None:

-            print(fn( bnf.parseString( strg ) ))

-        else:

-            print()

-

 digits = "0123456789"

 

 # Version 1

-element = Regex("A[cglmrstu]|B[aehikr]?|C[adeflmorsu]?|D[bsy]|"

-                "E[rsu]|F[emr]?|G[ade]|H[efgos]?|I[nr]?|Kr?|L[airu]|"

-                "M[dgnot]|N[abdeiop]?|Os?|P[abdmortu]?|R[abefghnu]|"

-                "S[bcegimnr]?|T[abcehilm]|U(u[bhopqst])?|V|W|Xe|Yb?|Z[nr]")

-

 element = Word( alphas.upper(), alphas.lower(), max=2)

+# for stricter matching, use this Regex instead

+# element = Regex("A[cglmrstu]|B[aehikr]?|C[adeflmorsu]?|D[bsy]|"

+#                 "E[rsu]|F[emr]?|G[ade]|H[efgos]?|I[nr]?|Kr?|L[airu]|"

+#                 "M[dgnot]|N[abdeiop]?|Os?|P[abdmortu]?|R[abefghnu]|"

+#                 "S[bcegimnr]?|T[abcehilm]|U(u[bhopqst])?|V|W|Xe|Yb?|Z[nr]")

 elementRef = Group( element + Optional( Word( digits ), default="1" ) )

 formula = OneOrMore( elementRef )

 

 fn = lambda elemList : sum(atomicWeight[elem]*int(qty) for elem,qty in elemList)

-test( formula, "H2O", fn )

-test( formula, "C6H5OH", fn )

-test( formula, "NaCl", fn )

+formula.runTests("""\

+    H2O

+    C6H5OH

+    NaCl

+    """,

+    fullDump=False, postParse=lambda _, tokens: "Molecular weight: {}".format(fn(tokens)))

 print()

 

-# Version 2 - access parsed items by field name

+# Version 2 - access parsed items by results name

 elementRef = Group( element("symbol") + Optional( Word( digits ), default="1" )("qty") )

 formula = OneOrMore( elementRef )

 

 fn = lambda elemList : sum(atomicWeight[elem.symbol]*int(elem.qty) for elem in elemList)

-test( formula, "H2O", fn )

-test( formula, "C6H5OH", fn )

-test( formula, "NaCl", fn )

+formula.runTests("""\

+    H2O

+    C6H5OH

+    NaCl

+    """,

+    fullDump=False, postParse=lambda _, tokens: "Molecular weight: {}".format(fn(tokens)))

 print()

 

 # Version 3 - convert integers during parsing process

@@ -59,6 +56,30 @@ elementRef = Group( element("symbol") + Optional( integer, default=1 )("qty") )
 formula = OneOrMore( elementRef )

 

 fn = lambda elemList : sum(atomicWeight[elem.symbol]*elem.qty for elem in elemList)

-test( formula, "H2O", fn )

-test( formula, "C6H5OH", fn )

-test( formula, "NaCl", fn )

+formula.runTests("""\

+    H2O

+    C6H5OH

+    NaCl

+    """,

+    fullDump=False, postParse=lambda _, tokens: "Molecular weight: {}".format(fn(tokens)))

+print()

+

+# Version 4 - parse and convert integers as subscript digits

+subscript_digits = "₀₁₂₃₄₅₆₇₈₉"

+subscript_int_map = dict((e[1], e[0]) for e in enumerate(subscript_digits))

+def cvt_subscript_int(s):

+    ret = 0

+    for c in s[0]:

+        ret = ret*10 + subscript_int_map[c]

+    return ret

+subscript_int = Word(subscript_digits).addParseAction(cvt_subscript_int)

+

+elementRef = Group( element("symbol") + Optional(subscript_int, default=1)("qty") )

+formula = OneOrMore( elementRef )

+formula.runTests("""\

+    H₂O

+    C₆H₅OH

+    NaCl

+    """,

+    fullDump=False, postParse=lambda _, tokens: "Molecular weight: {}".format(fn(tokens)))

+print()