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Why is null an object and what's the difference between null and undefined?
...n short; undefined is where no notion of the thing exists; it has no type, and it's never been referenced before in that scope; null is where the thing is known to exist, but it's not known what the value is.
One thing to remember is that null is not, conceptually, the same as false or "" or such, e...
Inline labels in Matplotlib
...below). This can be very fiddly, because I have to specify coordinates by hand, and, if I re-format the plot, I probably have to reposition the labels. Is there a way to automatically generate labels on curves in Matplotlib? Bonus points for being able to orient the text at an angle corresponding to...
How to sum a variable by group
...umns. First column contains categories such as "First", "Second", "Third", and the second column has numbers that represent the number of times I saw the specific groups from "Category".
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Displaying the build date
... have an app displaying the build number in its title window. That's well and good except it means nothing to most of the users, who want to know if they have the latest build - they tend to refer to it as "last Thursday's" rather than build 1.0.8.4321.
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Change column type from string to float in Pandas
I want to convert a table, represented as a list of lists, into a Pandas DataFrame . As an extremely simplified example:
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Div width 100% minus fixed amount of pixels
...hout using tables or JavaScript? The white borders represent edges of divs and aren't relevant to the question.
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Excel: last character/string match in a string
... position of a character/string's last occurrence in a string. Search and find both work left-to-right so I can't think how to apply without lengthy recursive algorithm. And this solution now seems obsolete.
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How can I quantify difference between two images?
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General idea
Option 1: Load both images as arrays (scipy.misc.imread) and calculate an element-wise (pixel-by-pixel) difference. Calculate the norm of the difference.
Option 2: Load both images. Calculate some feature vector for each of them (like a histogram). Calculate distance between featu...
Column order manipulation using col-lg-push and col-lg-pull in Twitter Bootstrap 3
I'm now reading documentation on Twitter Bootstrap 3, and tried to follow column ordering as shown in this page but hit the wall. I don't understand why such a code works nor how to correctly specify the setting. What I want to show is one grid, which is consisted of length 5, and the other leng...
What is the MySQL VARCHAR max size?
...ySQL table has a maximum row size limit of 65,535 bytes, not counting BLOB and TEXT types. BLOB and TEXT columns only contribute 9 to 12 bytes toward the row size limit because their contents are stored separately from the rest of the row. Read more about Limits on Table Column Count and Row Size.
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