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Apply pandas function to column to create multiple new columns?
...3 1.100880 -0.899120
4 1.017859 -0.982141
Editing for completeness
pd.concat([df, df.textcol.apply(lambda s: pd.Series({'feature1':s+1, 'feature2':s-1}))], axis=1)
textcol feature1 feature2
0 0.626524 1.626524 -0.373476
1 0.119967 1.119967 -0.880033
2 0.803650 1.803650 -0.196350
3 0.10...
LINQ order by null column where order is ascending and nulls should be last
... descending
orderby p.LowestPrice descending
select p;
will be translated by the compiler to
var products = _context.Products
.Where(p => p.ProductTypeId == 1)
.OrderByDescending(p => p.LowestPrice.HasValue)
...
Method Overloading for null argument
... an explicit "null" (yet implicit null type) argument always unambiguously selects a specific overload ??
– peterk
Jul 18 '17 at 21:43
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In log4j, does checking isDebugEnabled before logging improve performance?
...g statement you will already have the check in place.
2- You don't have to selectively include the statement on "complex" debug statements. All statements are included that way.
3- Calling log.debug executes the following before logging:
if(repository.isDisabled(Level.DEBUG_INT))
retur...
String Concatenation using '+' operator
... see the operators == and != overloaded. So how is it able to perform concatenation for the ' + ' operator?
1 Answer
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How do I escape a single quote in SQL Server?
...lue] VARCHAR(200)
)
INSERT INTO @my_table VALUES ('hi, my name''s tim.')
SELECT * FROM @my_table
Results
value
==================
hi, my name's tim.
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T-SQL CASE Clause: How to specify WHEN NULL
...
Given your query you can also do this:
SELECT first_name + ' ' + ISNULL(last_name, '') AS Name FROM dbo.person
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Find and extract a number from a string
...n(string.Empty, Regex.Matches(subjectString, @"\d+").OfType<Match>().Select(m => m.Value));
– Markus
Jul 26 '14 at 4:53
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Nginx缓存解决方案：SRCache - 更多技术 - 清泛网 - 专注C/C++及内核技术
..."?"
key[#key + 1] = query
end
key = table.concat(key)
key = ngx.md5(key)
ngx.var.phoenix_key = key
local now = ngx.time()
if ngx.var.arg_phoenix == true then
ngx.var.phoenix_fetch_skip = 0
else
...
Is there a JavaScript function that can pad a string to get to a determined length?
...n just appends to string to be added to this pre-padded string (one string concat) and then slices or trims the result to the desired length.
function pad(pad, str, padLeft) {
if (typeof str === 'undefined')
return pad;
if (padLeft) {
return (pad + str).slice(-pad.length);
} else {
...