1 files changed, 68 insertions, 0 deletions
diff --git a/examples/datetimeParseActions.py b/examples/datetimeParseActions.py
new file mode 100644
index 0000000..e42d2c6
--- /dev/null
+++ b/examples/datetimeParseActions.py
@@ -0,0 +1,68 @@
+# parseActions.py
+#
+#   A sample program a parser to match a date string of the form "YYYY/MM/DD",
+# and return it as a datetime, or raise an exception if not a valid date.
+#
+# Copyright 2012, Paul T. McGuire
+#
+from datetime import datetime
+from pyparsing import *
+
+# define an integer string, and a parse action to convert it
+# to an integer at parse time
+integer = Word(nums).setName("integer")
+def convertToInt(tokens):
+    # no need to test for validity - we can't get here
+    # unless tokens[0] contains all numeric digits
+    return int(tokens[0])
+integer.setParseAction(convertToInt)
+# or can be written as one line as
+#integer = Word(nums).setParseAction(lambda t: int(t[0]))
+
+# define a pattern for a year/month/day date
+date_expr = integer('year') + '/' + integer('month') + '/' + integer('day')
+date_expr.ignore(pythonStyleComment)
+
+def convertToDatetime(s,loc,tokens):
+    try:
+        # note that the year, month, and day fields were already
+        # converted to ints from strings by the parse action defined
+        # on the integer expression above
+        return datetime(tokens.year, tokens.month, tokens.day).date()
+    except Exception as ve:
+        errmsg = "'%s/%s/%s' is not a valid date, %s" % \
+            (tokens.year, tokens.month, tokens.day, ve)
+        raise ParseException(s, loc, errmsg)
+date_expr.setParseAction(convertToDatetime)
+
+
+date_expr.runTests("""\
+    2000/1/1 
+
+    # invalid month
+    2000/13/1  
+
+    # 1900 was not a leap year
+    1900/2/29  
+
+    # but 2000 was
+    2000/2/29  
+    """)
+
+
+# if dates conform to ISO8601, use definitions in pyparsing_common
+date_expr = pyparsing_common.iso8601_date.setParseAction(pyparsing_common.convertToDate())
+date_expr.ignore(pythonStyleComment)
+
+date_expr.runTests("""\
+    2000-01-01 
+
+    # invalid month
+    2000-13-01  
+
+    # 1900 was not a leap year
+    1900-02-29  
+
+    # but 2000 was
+    2000-02-29  
+    """)
+\ No newline at end of file