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How do I copy a file in Python?
...sts, it will be replaced.
Special files such as character or block devices and pipes cannot be copied with this function.
With copy, src and dst are path names given as strings.
If you use os.path operations, use copy rather than copyfile. copyfile will only accept strings.
...
Should I use #define, enum or const?
...Assuming you have ruled out bitset, I vote for the enum.
I don't buy that casting the enums is a serious disadvantage - OK so it's a bit noisy, and assigning an out-of-range value to an enum is undefined behaviour so it's theoretically possible to shoot yourself in the foot on some unusual C++ impl...
Java array reflection: isArray vs. instanceof
...er an object is an array.
Generally, you test an object's type before downcasting to a particular type which is known at compile time. For example, perhaps you wrote some code that can work with a Integer[] or an int[]. You'd want to guard your casts with instanceof:
if (obj instanceof Integer[]) ...
How can I build a small operating system on an old desktop computer? [closed]
...things first. Read, read, read, read, read. You need to have a firm understanding of how the OS works before you can hope to implement your own.
Grab one of Andrew Tanenbaum's books on operating systems. This is the one we used in my OS class in college:
Modern Operating Systems PDF
Modern Op...
Detect if value is number in MySQL
...('12.e-5'),('3.5e+6'),('a'),('e6'),('+e0');
select
col1,
col1 + 0 as casted,
col1 REGEXP '^[+-]?[0-9]*([0-9]\\.|[0-9]|\\.[0-9])[0-9]*(e[+-]?[0-9]+)?$' as isNumeric
from myTable;
Result:
col1 | casted | isNumeric
-------|---------|----------
00.00 | 0 | 1
+1 | 1...
php is null or empty?
... @Robert: A string not starting with digits is converted to 0 when cast to a string: codepad.org/qi40SG3E. So (int)"php" == 0.
– Felix Kling
Nov 27 '13 at 21:58
...
How to export all data from table to an insertable sql format?
...nvarchar (max) = ''
DECLARE @Columns nvarchar(max)
DECLARE @ColumnsCast nvarchar(max)
-- cleanUp/prepraring data
SET @SchemaName = REPLACE(REPLACE(@SchemaName,'[',''),']','')
SET @TableName = REPLACE(REPLACE(@TableName,'[',''),']','')
SET @AsFileNAme = NULLIF(@AsFileNAme,'')...
How do you properly determine the current script directory in Python?
...at if you would be able to define a "known location" that is multiplatform and that also comes with the module. I'm ready to bet that the only safe location is the script location. Note, this doesn't meat that the script should write to this location, but for reading data it is safe.
...
python: Change the scripts working directory to the script's own directory
... @EliCourtwright If __file__ is not already an absolute path, and the user has changed the working directory, then os.path.abspath will fail anyway.
– Arthur Tacca
Jan 17 '17 at 16:16
...
How can mixed data types (int, float, char, etc) be stored in an array?
... x = r;
x.val = 25.0;
}
integer g = { INT, 100 };
record rg = g;
Up-casting and down-casting.
Edit: One gotcha to be aware of is if you're constructing one of these with C99 designated initializers. All member initializers should be through the same union member.
record problem = { .tag ...