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Python circular importing?
... of it) for the first time, the code inside the module is executed sequentially like any other code; e.g., it is not treated any differently that the body of a function. An import is just a command like any other (assignment, a function call, def, class). Assuming your imports occur at the top of th...
List of foreign keys and the tables they reference
...key is described in the columns r_owner and r_constraint_name of the table ALL_CONSTRAINTS. This will give you the info you want:
SELECT a.table_name, a.column_name, a.constraint_name, c.owner,
-- referenced pk
c.r_owner, c_pk.table_name r_table_name, c_pk.constraint_name r_pk
FROM...
Pragma in define macro
...ay of doing that. Then again, there are no portable ways to use #pragma at all. Because of this, many C/C++ compilers define their own methods for doing pragma-like things, and they often can be embedded in macros, but you need a different macro definition on every compiler. If you are willing to go...
How to model type-safe enum types?
...ample above) does not offer exhaustive pattern matching. I have researched all the different enumeration patterns currently being used in Scala and give and overview of them in this StackOverflow answer (including a new pattern which offers the best of both scala.Enumeration and the "sealed trait +...
What is a stream?
...
A stream represents a sequence of objects (usually bytes, but not necessarily so), which can be accessed in sequential order. Typical operations on a stream:
read one byte. Next time you read, you'll get the next byte, and so on.
read several bytes from the stream into...
sql “LIKE” equivalent in django query
...s. I have made the lookup into a Django-like-lookup application. After installing it the __like lookup with the % and _ wildcards will be enabled.
All the necessary code in the application is:
from django.db.models import Lookup
from django.db.models.fields import Field
@Field.register_lookup
cl...
How do I look inside a Python object?
...-in functions:
type()
dir()
id()
getattr()
hasattr()
globals()
locals()
callable()
type() and dir() are particularly useful for inspecting the type of an object and its set of attributes, respectively.
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What is the _snowman param in Ruby on Rails 3 forms for?
...net Explorer (5, 6, 7 and 8) to encode its parameters as unicode.
Specifically, this bug can be triggered if the user switches the browser's encoding to Latin-1. To understand why a user would decide to do something seemingly so crazy, check out this google search. Once the user has put the web-sit...
Django ManyToMany filter()
...nes__in=[zone1, zone2, zone3])
The double underscore (__) syntax is used all over the place when working with querysets.
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How to ALTER multiple columns at once in SQL Server
.... Each statement means a new scan but if you could alter multiple columns, all altering could have been much quicker
– erikkallen
Sep 8 '16 at 6:31
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