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Aren't Python strings immutable? Then why does a + “ ” + b work?

...the variable a to point at a new string "Dog eats treats". You didn't actually mutate the string "Dog". Strings are immutable, variables can point at whatever they want. share | improve this answe...
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What is your single most favorite command-line trick using Bash? [closed]

We all know how to use <ctrl>-R to reverse search through history, but did you know you can use <ctrl>-S to forward search if you set stty stop "" ? Also, have you ever tried running bind -p to see all of your keyboard shortcuts listed? There are over 455 on Mac OS X by default. ...
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How to crop an image in OpenCV using Python

...copy region of interest If we consider (0,0) as top left corner of image called im with left-to-right as x direction and top-to-bottom as y direction. and we have (x1,y1) as the top-left vertex and (x2,y2) as the bottom-right vertex of a rectangle region within that image, then: roi = im[y1:y2, x1...
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Convert string to Python class object?

... there's a class with that name in the currently defined namespace. Essentially, I want the implementation for a function which will produce this kind of result: ...
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Python Linked List

...le to reference separate parts of them. Make them immutable and they are really easy to work with! 28 Answers ...
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Is there an expression for an infinite generator?

... for x in iter(int, 1): pass Two-argument iter = zero-argument callable + sentinel value int() always returns 0 Therefore, iter(int, 1) is an infinite iterator. There are obviously a huge number of variations on this particular theme (especially once you add lambda into the mix). One va...
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What does the variable $this mean in PHP?

I see the variable $this in PHP all the time and I have no idea what it's used for. I've never personally used it. 10 An...
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How to add an extra column to a NumPy array

...for a way to add a bias unit to my artificial neuronal network in batch on all layers at once, and this is the perfect answer. – gaborous Aug 18 '16 at 15:07 ...
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Open link in new tab or window [duplicate]

... It shouldn't be your call to decide whether the link should open in a new tab or a new window, since ultimately this choice should be done by the settings of the user's browser. Some people like tabs; some like new windows. Using _blank will tell...
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Perform commands over ssh with Python

...to automate some command line commands in Python. At the moment I'm doing calls thus: 13 Answers ...