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Parsing boolean values with argparse
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I recommend mgilson's answer but with a mutually exclusive group
so that you cannot use --feature and --no-feature at the same time.
command --feature
and
command --no-feature
but not
command --feature --no-feature
Script:
feature_parser = parser.add_mutually_exclusive_grou...
Is there a regular expression to detect a valid regular expression?
... # start of string
( # first group start
(?:
(?:[^?+*{}()[\]\\|]+ # literals and ^, $
| \\. # escaped characters
| \[ (?: \^?\\. | \^[^\\] | [^\\^] ) # character classes
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SELECT DISTINCT on one column
...ry for finding the minimum ID matching your query. In the subquery you use GROUP BY instead of DISTINCT:
SELECT * FROM [TestData] WHERE [ID] IN (
SELECT MIN([ID]) FROM [TestData]
WHERE [SKU] LIKE 'FOO-%'
GROUP BY [PRODUCT]
)
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Is it worth using Python's re.compile?
...e, though - e.g. if you define the regex in one place and use its matching groups in another far-away place.
– Ken Williams
Jul 17 '17 at 15:51
1
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Setting up a git remote origin
... you might expect:
git remote add --track master origin user@somesite.com:group/project.git # git
git remote add --track master origin user@172.16.1.100:group/project.git # git w/IP
git remote add --track master origin http://github.com/group/project.git # http
git remote add --track master o...
JSR-303 @Valid annotation not working for list of child objects
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What about grouping? I want address to be validated only when group A is validated. @Valid ignores the group.
– Akshay
Jan 3 '17 at 13:09
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SQL selecting rows by most recent date
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You can use a GROUP BY to group items by type and id. Then you can use the MAX() Aggregate function to get the most recent service month. The below returns a result set with ChargeId, ChargeType, and MostRecentServiceMonth
SELECT
CHAR...
Hidden Features of MySQL
...OM mytable ORDER BY virtualcolumn
http://dev.mysql.com/doc/refman/5.0/en/group-by-hidden-fields.html
http://dev.mysql.com/doc/refman/5.1/en/information-functions.html#function_last-insert-id
last_insert_id()
gets you the PK of the last row inserted in the current thread max(pkcolname) gets you ...
INSERT INTO … SELECT FROM … ON DUPLICATE KEY UPDATE
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Note: This will not work when SELECT statement has a GROUP BY clause
– joHN
Jul 30 '14 at 11:44
11
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How to randomly select an item from a list?
...item from a set, I'd recommend using random.sample instead.
import random
group_of_items = {1, 2, 3, 4} # a sequence or set will work here.
num_to_select = 2 # set the number to select here.
list_of_random_items = random.sample(group_of_items, num_to_select)
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