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How to avoid isset() and empty()
...of "xyz is undefined" and "undefined offset" messages when running on the E_NOTICE error level, because the existence of variables is not explicitly checked using isset() and consorts.
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How to verify if a file exists in a batch file?
...ing
)
If you do not need an "else", you can do something like this:
set __myVariable=
IF EXIST "C:\folder with space\myfile.txt" set __myVariable=C:\folder with space\myfile.txt
IF EXIST "C:\some other folder with space\myfile.txt" set __myVariable=C:\some other folder with space\myfile.txt
set _...
“Code too large” compilation error in Java
... of a method must not be bigger than 65536 bytes:
The value of the code_length item gives the number of bytes in the code array for this method.
The value of code_length must be greater than zero (as the code array must not be empty) and less than 65536.
code_length defines the size of th...
Python: most idiomatic way to convert None to empty string?
...ot ''. s(0) should return '0', not ''. Likewise for an object that defines __bool__ or __nonzero__.
– Oddthinking
May 13 '17 at 3:27
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Django database query: How to get object by id?
...ject, using get() is more straightforward:
obj = Class.objects.get(pk=this_object_id)
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Can PostgreSQL index array columns?
...0}');
INSERT INTO "Test" VALUES ('{10, 20, 30}');
CREATE INDEX idx_test on "Test" USING GIN ("Column1");
-- To enforce index usage because we have only 2 records for this test...
SET enable_seqscan TO off;
EXPLAIN ANALYZE
SELECT * FROM "Test" WHERE "Column1" @> ARRAY[2...
Regular expression to allow spaces between words
...
tl;dr
Just add a space in your character class.
^[a-zA-Z0-9_ ]*$
Now, if you want to be strict...
The above isn't exactly correct. Due to the fact that * means zero or more, it would match all of the following cases that one would not usually mean to match:
An empty string...
Adding a new value to an existing ENUM Type
...he new type.
-- 1. rename the enum type you want to change
alter type some_enum_type rename to _some_enum_type;
-- 2. create new type
create type some_enum_type as enum ('old', 'values', 'and', 'new', 'ones');
-- 3. rename column(s) which uses our enum type
alter table some_table rename column some...
Programmatically retrieve memory usage on iPhone
...icture of usage over-all.
#import <mach/mach.h>
// ...
void report_memory(void) {
struct task_basic_info info;
mach_msg_type_number_t size = TASK_BASIC_INFO_COUNT;
kern_return_t kerr = task_info(mach_task_self(),
TASK_BASIC_INFO,
...
Should all Python classes extend object?
...;>> class Bar(object): pass
...
>>> type(Bar())
<class '__main__.Bar'>
Also the rules for multiple inheritance are different in ways that I won't even try to summarize here. All good documentation that I've seen about MI describes new-style classes.
Finally, old-style classe...