Added new example parseTabularData.py

Updated several examples to more current Python and pyparsing practices (and better Py2/Py3 cross-compatibility)

1 files changed, 20 insertions, 23 deletions

diff --git a/src/examples/rangeCheck.py b/src/examples/rangeCheck.py
index 35c9ef3..59bd49c 100644
--- a/src/examples/rangeCheck.py
+++ b/src/examples/rangeCheck.py
@@ -3,46 +3,42 @@
 #   A sample program showing how parse actions can convert parsed 

 # strings into a data type or object, and to validate the parsed value.

 #

-# Copyright 2011, Paul T. McGuire

+# Updated to use new addCondition method and expr() copy.

+#

+# Copyright 2011,2015 Paul T. McGuire

 #

 

 from pyparsing import Word, nums, Suppress, ParseException, empty, Optional

 from datetime import datetime

 

-def rangeCheck(minval=None, maxval=None):

+def ranged_value(expr, minval=None, maxval=None):

     # have to specify at least one range boundary

     if minval is None and maxval is None:

         raise ValueError("minval or maxval must be specified")

-        

+

     # set range testing function and error message depending on

     # whether either or both min and max values are given

-    inRangeFn = {

-        (True, False)  : lambda x : x <= maxval,

-        (False, True)  : lambda x : minval <= x,

-        (False, False) : lambda x : minval <= x <= maxval,

+    inRangeCondition = {

+        (True, False)  : lambda s,l,t : t[0] <= maxval,

+        (False, True)  : lambda s,l,t : minval <= t[0],

+        (False, False) : lambda s,l,t : minval <= t[0] <= maxval,

         }[minval is None, maxval is None]

     outOfRangeMessage = {

-        (True, False)  : "value %%s is greater than %s" % maxval,

-        (False, True)  : "value %%s is less than %s" % minval,

-        (False, False) : "value %%s is not in the range (%s to %s)" % (minval,maxval),

+        (True, False)  : "value is greater than %s" % maxval,

+        (False, True)  : "value is less than %s" % minval,

+        (False, False) : "value is not in the range (%s to %s)" % (minval,maxval),

         }[minval is None, maxval is None]

 

-    # define the actual range checking parse action

-    def rangeCheckParseAction(string, loc, tokens):

-        parsedval = tokens[0]

-        if not inRangeFn(parsedval):

-            raise ParseException(string, loc, outOfRangeMessage % parsedval)

-

-    return rangeCheckParseAction

+    return expr().addCondition(inRangeCondition, message=outOfRangeMessage)

 

 # define the expressions for a date of the form YYYY/MM/DD or YYYY/MM (assumes YYYY/MM/01)

 integer = Word(nums).setName("integer")

 integer.setParseAction(lambda t:int(t[0]))

 

-month = integer.copy().addParseAction(rangeCheck(1,12))

-day = integer.copy().addParseAction(rangeCheck(1,31))

-year = integer.copy().addParseAction(rangeCheck(2000, None))

-

+month = ranged_value(integer, 1, 12)

+day = ranged_value(integer, 1, 31)

+year = ranged_value(integer, 2000, None)

+    

 SLASH = Suppress('/')

 dateExpr = year("year") + SLASH + month("month") + Optional(SLASH + day("day"))

 dateExpr.setName("date")

@@ -53,7 +49,7 @@ dateExpr.setParseAction(lambda t: datetime(t.year, t.month, t.day or 1).date())
 # add range checking on dates

 mindate = datetime(2002,1,1).date()

 maxdate = datetime.now().date()

-dateExpr.addParseAction(rangeCheck(mindate, maxdate))

+dateExpr = ranged_value(dateExpr, mindate, maxdate)

 

 

 tests = """

@@ -62,6 +58,7 @@ tests = """
     2004/2/29

     2004/2/30

     2004/2

+    1999/12/31

     """.splitlines()

 for t in tests:

     t = t.strip()

@@ -71,6 +68,6 @@ for t in tests:
         print(dateExpr.parseString(t)[0])

     except Exception as e:

         print(str(e))

-    print()

+    print('')