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When converting a project to use ARC what does “switch case is in protected scope” mean?
...t fixed the compile problem:
NSDate *from; /* <----------- */
switch (index) {
....
case 2:
from = [NSDate dateWithTimeIntervalSince1970:1388552400];
[self refreshContents:from toDate:[NSDate date]];
break;
}
...
Drop columns whose name contains a specific string from pandas DataFrame
....contains
In recent versions of pandas, you can use string methods on the index and columns. Here, str.startswith seems like a good fit.
To remove all columns starting with a given substring:
df.columns.str.startswith('Test')
# array([ True, False, False, False])
df.loc[:,~df.columns.str.startsw...
How many characters can a Java String have?
...o 2^31-1 characters, as they are held by an internal array, and arrays are indexed by integers in Java.
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Only variables should be passed by reference
...
Just as you can't index the array immediately, you can't call end on it either. Assign it to a variable first, then call end.
$basenameAndExtension = explode('.', $file_name);
$ext = end($basenameAndExtension);
...
Opacity of background-color, but not the text [duplicate]
...}
div::before
{
content: "";
display: block;
position: absolute;
z-index: -1;
width: 100%;
height: 100%;
background:red;
opacity: .2;
}
Demo at http://jsfiddle.net/KVyFH/172/
It will work on any modern browser
...
When does a process get SIGABRT (signal 6)?
...
In my case, it was due to an input in an array at an index equal to the length of the array.
string x[5];
for(int i=1; i<=5; i++){
cin>>x[i];
}
x[5] is being accessed which is not present.
...
How do I find duplicate values in a table in Oracle?
..._NAME
AND ROWID < A.ROWID
)
Works fine (quick enough) when there is index on column_name. And it's better way to delete or update duplicate rows.
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Linux下部署企业级邮件服务器(postfix + dovecot + extmail) - 开源 & Gith...
...原理：
当用户通过extmail登陆时，首先extmail先去通过mysql进行虚拟用户认证，当认证通过时，postfix通过Cyrus-SASL这个函数库，这个认证框架，结合Courier-authlib对发信人进行认证，通过检索Mysql数据库中的数据来进行认证，以此来...
MySQL select where column is not empty
...nd another plus over the COALESCE() and IFNULL() functions is that this is index friendly, since you're not comparing the output of a function on a field to anything.
Test cases:
SELECT if(NULL > '','true','false');-- false
SELECT if('' > '','true','false');-- false
SELECT if(' ' > '','tr...
How to get the filename without the extension from a path in Python?
...elp deal with the multiple dots problem. The answer below about using the index will not work if the path is './foo.tar.gz'
– William Allcock
Feb 12 at 22:51
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