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How do I avoid capturing self in blocks when implementing an API?
I have a working app and I'm working on converting it to ARC in Xcode 4.2. One of the pre-check warnings involves capturing self strongly in a block leading to a retain cycle. I've made a simple code sample to illustrate the issue. I believe I understand what this means but I'm not sure the "corre...
What does “hashable” mean in Python?
...ue which never changes during its lifetime (it needs a __hash__() method), and can be compared to other objects (it needs an __eq__() or __cmp__() method). Hashable objects which compare equal must have the same hash value.
Hashability makes an object usable as a dictionary key and a set member...
Python multiprocessing pool.map for multiple arguments
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The answer to this is version- and situation-dependent. The most general answer for recent versions of Python (since 3.3) was first described below by J.F. Sebastian.1 It uses the Pool.starmap method, which accepts a sequence of argument tuples. It then au...
Exiting from python Command Line
To exit from Python command line, I have to type exit(). If I type exit, it says
11 Answers
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Format date and time in a Windows batch script
In a Windows (Windows XP) batch script I need to format the current date and time for later use in files names, etc.
33 An...
How to import other Python files?
...t__): Because this function is meant for use by the Python interpreter and not for general use it is better to use importlib.import_module() to programmatically import a module.
– Tadhg McDonald-Jensen
Feb 23 '16 at 15:04
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How do I plot in real-time in a while loop using matplotlib?
...ib.pyplot as plt
plt.axis([0, 10, 0, 1])
for i in range(10):
y = np.random.random()
plt.scatter(i, y)
plt.pause(0.05)
plt.show()
Note some of the changes:
Call plt.pause(0.05) to both draw the new data and it runs the GUI's event loop (allowing for mouse interaction).
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What's the difference between globals(), locals(), and vars()?
What is the difference between globals() , locals() , and vars() ? What do they return? Are updates to the results useful?
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Lazy Method for Reading Big File in Python?
I have a very big file 4GB and when I try to read it my computer hangs.
So I want to read it piece by piece and after processing each piece store the processed piece into another file and read next piece.
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What does the caret operator (^) in Python do?
I ran across the caret operator in python today and trying it out, I got the following output:
5 Answers
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