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Removing all non-numeric characters from string in Python
... this is the most efficient way, but:
>>> ''.join(c for c in "abc123def456" if c.isdigit())
'123456'
The ''.join part means to combine all the resulting characters together without any characters in between. Then the rest of it is a list comprehension, where (as you can probably guess) ...
SQL JOIN - WHERE clause vs. ON clause
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@JamesHutchison It's tough to make reliable performance generalizations based on observed behaviors like this. What was true one day tends to be wrong the next, because this is an implementation detail rather than documented behavior. Database teams are always look...
Test whether string is a valid integer
...of "+" (e.g. +30) which obviously is an integer.
Results:
$ int_check.sh 123
123 is an integer !!
$ int_check.sh 123+
ERROR: first parameter must be an integer.
$ int_check.sh -123
-123 is an integer !!
$ int_check.sh +30
+30 is an integer !!
$ int_check.sh -123c
ERROR: first parameter must be...
How can I pad a String in Java?
...*chars
Display '*' for characters of password:
String password = "secret123";
String padded = String.format("%"+password.length()+"s", "").replace(' ', '*');
output has the same length as the password string:
secret123
*********
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How to iterate through a DataTable
I need to iterate through a DataTable . I have an column there named ImagePath .
4 Answers
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编程基础与事件状态 04：用状态机处理暂停和重复点击 · App Inventor 2 中文网
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How to get the data-id attribute?
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To get the contents of the attribute data-id (like in <a data-id="123">link</a>) you have to use
$(this).attr("data-id") // will return the string "123"
or .data() (if you use newer jQuery >= 1.4.3)
$(this).data("id") // will return the number 123
and the part after data- ...
编程基础与事件状态 01：让按钮响应你的任务 · App Inventor 2 中文网
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Easiest way to detect Internet connection on iOS?
...through HTTPUrlConnection instantly fail if there is no connection available. This seems like completely sane behavior, and I was surprised to find NSURLConnection in iOS did not emulate it.
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游戏中的算法与计算思维 06：用难度与耗时形成游戏规则 · App Inventor 2 中文网
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