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When is del useful in python?
...here may be others, but I know about this one off hand) when you are using sys.exc_info() to inspect an exception. This function returns a tuple, the type of exception that was raised, the message, and a traceback.
The first two values are usually sufficient to diagnose an error and act on it, b...
Converting int to bytes in Python 3
...s much more expensive, so never use lists when you can use tuples. You can convert bigger integers by using int.to_bytes(3, "little").
Initializing bytes with a given length makes sense and is the most useful, as they are often used to create some type of buffer for which you need some memory of gi...
Why can't I use a list as a dict key in python?
...
Why not just convert the list to a tuple? Why convert it to a string? If you use a tuple, it'll work correctly with classes that have a custom comparison method __eq__. But if you convert them to strings, everything is compared by its str...
Assign pandas dataframe column dtypes
... pd.to_timedelta and pd.to_numeric
(As mentioned below, no more "magic", convert_objects has been deprecated in 0.17)
df = pd.DataFrame({'x': {0: 'a', 1: 'b'}, 'y': {0: '1', 1: '2'}, 'z': {0: '2018-05-01', 1: '2018-05-02'}})
df.dtypes
x object
y object
z object
dtype: object
df
x ...
How to convert a boolean array to an int array
I use Scilab, and want to convert an array of booleans into an array of integers:
6 Answers
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How can I convert bigint (UNIX timestamp) to datetime in SQL Server?
How can I convert UNIX timestamp (bigint) to DateTime in SQL Server?
15 Answers
15
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Formatting Numbers by padding with leading zeros in SQL Server
...)) + EmployeeId
If the column is an INT, you can use RTRIM to implicitly convert it to a VARCHAR
SELECT REPLICATE('0',6-LEN(RTRIM(EmployeeId))) + RTRIM(EmployeeId)
And the code to remove these 0s and get back the 'real' number:
SELECT RIGHT(EmployeeId,(LEN(EmployeeId) - PATINDEX('%[^0]%',Empl...
Converting Stream to String and back…what are we missing?
...s to a formatted string
a formatted string to the original bytes
look at Convert.ToBase64String and Convert. FromBase64String
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What's the strangest corner case you've seen in C# or .NET? [closed]
... the amount of points given to customers. The issue was related to casting/converting double to int.
In code below:
double d = 13.6;
int i1 = Convert.ToInt32(d);
int i2 = (int)d;
does i1 == i2 ?
It turns out that i1 != i2.
Because of different rounding policies in Convert and cast operator the...
How to check if a Constraint exists in Sql server?
...rent_object_id) AS TableName
,type_desc AS ConstraintType
FROM sys.objects
WHERE type_desc LIKE '%CONSTRAINT'
AND OBJECT_NAME(OBJECT_ID)='XYZ'
If you need even more constraint information, look inside the system stored procedure master.sys.sp_helpconstraint to see how to ge...