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Relational table naming convention [closed]
...g relations, identifying errors, and correcting the table names.
Diagram_A
Of course, the relationship is implemented in SQL as a CONSTRAINT FOREIGN KEY in the child table (more, later). Here is the Verb Phrase (in the model), the Predicate that it represents (to be read from the model), and th...
Efficient way to apply multiple filters to pandas DataFrame or Series
...turn op(x[col],n)
In [15]: def f(x, *b):
return x[(np.logical_and(*b))]
In [16]: b1 = b(df, 'col1', ge, 1)
In [17]: b2 = b(df, 'col1', le, 1)
In [18]: f(df, b1, b2)
Out[18]:
col1 col2
1 1 11
Update: pandas 0.13 has a query method for these kind of use cases, assuming c...
setuptools: package data folder location
...or example, if I have a project layout like so:
project/
foo/
__init__.py
data/
resource1/
foo.txt
You can add a function to __init__.py to locate an absolute path to a data
file:
import os
_ROOT = os.path.abspath(os.path.dirname(__file__))
def g...
How to check BLAS/LAPACK linkage in NumPy and SciPy?
...
The method numpy.show_config() (or numpy.__config__.show()) outputs information about linkage gathered at build time. My output looks like this. I think it means I am using the BLAS/LAPACK that ships with Mac OS.
>>> import numpy as np...
How do you test that a Python function throws an exception?
...t ahold of the actual Exception object thrown:
import unittest
def broken_function():
raise Exception('This is broken')
class MyTestCase(unittest.TestCase):
def test(self):
with self.assertRaises(Exception) as context:
broken_function()
self.assertTrue('This i...
Difference between int32, int, int32_t, int8 and int8_t
I came across the data type int32_t in a C program recently. I know that it stores 32 bits, but don't int and int32 do the same?
...
Getting a list of all subdirectories in the current directory
...
Do not use os.walk('.').next()[1] or os.walk('.').__next__()[1] directly. Instead, use the built-in function next(), which is available both in Python 2 (see doc) and Python 3 (see doc). For example: next(os.walk('.'))[1].
– Lucio Paiva
...
Looping through a hash, or using an array in PowerShell
... how:
$hash = @{
a = 1
b = 2
c = 3
}
$hash.Keys | % { "key = $_ , value = " + $hash.Item($_) }
Output:
key = c , value = 3
key = a , value = 1
key = b , value = 2
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improve th...
Comparing mongoose _id and strings
...ls() method. With your example, results.userId.equals(AnotherMongoDocument._id). The ObjectID type also has a toString() method, if you wish to store a stringified version of the ObjectID in JSON format, or a cookie.
If you use ObjectID = require("mongodb").ObjectID (requires the mongodb-native lib...
How to detect total available/free disk space on the iPhone/iPad device?
...
Original answer:
I found the following solution working for me:
-(uint64_t)getFreeDiskspace {
uint64_t totalSpace = 0;
uint64_t totalFreeSpace = 0;
NSError *error = nil;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSDic...