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Why .NET String is immutable? [duplicate]
As we all know, String is immutable. What are the reasons for String being immutable and the introduction of StringBuilder class as mutable?
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Concatenating two one-dimensional NumPy arrays
... the input list in various ways before hand. np.stack for example adds an extra dimension to all input arrays. Look at their source code. Only concatenate is compiled.
– hpaulj
May 26 '17 at 16:45
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how to create a file name with the current date & time in python?
...ng datetime, this solves your problem (answers your question) of getting a string with the current time and date format you specify:
import time
timestr = time.strftime("%Y%m%d-%H%M%S")
print timestr
yields:
20120515-155045
so your filename could append or use this string.
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What is the proper way to format a multi-line dict in Python?
...(4, 'd'),
],
}
Similarly, here's my preferred way of including large strings without introducing any whitespace (like you'd get if you used triple-quoted multi-line strings):
data = (
"iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABG"
"l0RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAA...
What's wrong with nullable columns in composite primary keys?
...s version the "ext" part of the tuple is NOT NULL but defaults to an empty string -- which is semantically (and practically) different from a NULL. A NULL is an unknown, whereas an empty string is a deliberate record of "something not being present". In other words, "empty" and "null" are different ...
Starting python debugger automatically on error
...tically start pdb when an error is encountered? I am not against having an extra import statement at the top of the file, nor a few extra lines of code.
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Building a minimal plugin architecture in Python
...e too, although you can do a lot with just __import__, os.listdir and some string manipulation.
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Strings as Primary Keys in SQL Database [closed]
... slower from a performance standpoint (inserting/updating/querying) to use Strings for Primary Keys than integers?
15 Ans...
Catching an exception while using a Python 'with' statement
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@ncoghlan But you can add extra try...except blocks inside with to be closer to the source of an exception that doesn't have anything to do with open().
– rbaleksandar
May 19 '17 at 14:44
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PostgreSQL: Difference between text and varchar (character varying)
...tant increase of the length constraint, and on the basis that decreasing a string length constraint is rare, depesz concludes that one of them is usually the best choice for a length limit.
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