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| author | Cengiz Kaygusuz <cngkaygusuz@gmail.com> | 2017-11-20 20:46:39 -0500 |
|---|---|---|
| committer | Cengiz Kaygusuz <cngkaygusuz@gmail.com> | 2017-11-20 20:46:39 -0500 |
| commit | 27e183a78c8062ed7c2bbb91655a5e56cd697bba (patch) | |
| tree | 88fd355a0cc6da4c130582e092d702836596cbb2 /examples/rangeCheck.py | |
| parent | 4ba589cf13588e90992e23deb5a9784340efd2cc (diff) | |
| download | pyparsing-git-27e183a78c8062ed7c2bbb91655a5e56cd697bba.tar.gz | |
Move src to root
Diffstat (limited to 'examples/rangeCheck.py')
| -rw-r--r-- | examples/rangeCheck.py | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/examples/rangeCheck.py b/examples/rangeCheck.py new file mode 100644 index 0000000..67cf267 --- /dev/null +++ b/examples/rangeCheck.py @@ -0,0 +1,62 @@ +# rangeCheck.py
+#
+# A sample program showing how parse actions can convert parsed
+# strings into a data type or object, and to validate the parsed value.
+#
+# 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 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
+ 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 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]
+
+ 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 = 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")
+
+# convert date fields to datetime (also validates dates as truly valid dates)
+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 = ranged_value(dateExpr, mindate, maxdate)
+
+
+dateExpr.runTests("""
+ 2011/5/8
+ 2001/1/1
+ 2004/2/29
+ 2004/2
+ 1999/12/31""")
+
+
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