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What XML parser should I use in C++? [closed]
I have XML documents that I need to parse and/or I need to build XML documents and write them to text (either files or memory). Since the C++ standard library does not have a library for this, what should I use?
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pandas: multiple conditions while indexing data frame - unexpected behavior
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As you can see, the AND operator drops every row in which at least one
value equals -1. On the other hand, the OR operator requires both
values to be equal to -1 to drop them.
That's right. Remember that you're writing the condition in te...
When should I use @classmethod and when def method(self)?
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Your guess is correct - you understand how classmethods work.
The why is that these methods can be called both on an instance OR on the class (in both cases, the class object will be passed as the first argument):
class Dummy(object):
@classmethod
d...
What does the “yield” keyword do?
What is the use of the yield keyword in Python, and what does it do?
42 Answers
42
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INSERT IF NOT EXISTS ELSE UPDATE?
... the ID column: In the replacement case the statement would set it to NULL and then a fresh ID would be allocated.
This approach can also be used if you want to leave particular field values alone if the row in the replacement case but set the field to NULL in the insert case.
For example, assumin...
What is the difference between square brackets and parentheses in a regex?
.../^[789]\d{9}$/
/^[7-9]\d{9}$/
The explanation:
(a|b|c) is a regex "OR" and means "a or b or c", although the presence of brackets, necessary for the OR, also captures the digit. To be strictly equivalent, you would code (?:7|8|9) to make it a non capturing group.
[abc] is a "character class" th...
WatiN or Selenium? [closed]
... tests of our presentation soon. It seems that everyone recommends WatiN and Selenium . Which do you prefer for automated testing of ASP.NET web forms? Which of these products work better for you?
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What are the pros and cons of performing calculations in sql vs. in your application
...ed to access/aggregate a lot of data, doing it at the db server will save bandwidth, and disk io if the aggregates can be done inside indexes)
convenience (sql is not the best language for complex work - especially not great for procedural work, but very good for set-based work; lousy error-handling...
What data type to use for hashed password field and what length?
... @Hippo: Please, don't use the username as the salt. Generate a random salt per user.
– Bill Karwin
Sep 15 '10 at 18:38
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Switch statement fallthrough in C#?
... Damn - I've been programming with C# since the early days of 1.0, and I've never seen this until now. Just goes to show, you learn new things every day.
– Erik Forbes
Feb 5 '09 at 3:30
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