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How can I check if a string represents an int, without using try/except?
...0' format, which is similar to int casting in this sense.
edit:
def check_int(s):
if s[0] in ('-', '+'):
return s[1:].isdigit()
return s.isdigit()
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...
Why rename synthesized properties in iOS with leading underscores? [duplicate]
...ariables had to be instantiated explicitly:
@interface Foo : Bar {
Baz *_qux;
}
@property (retain) Baz *qux;
@end
@implementation Foo
@synthesize qux = _qux;
- (void)dealloc {
[_qux release];
[super dealloc];
}
@end
People would prefix their instance variables to differentiate them from...
Convert a row of a data frame to vector
...u have to be careful if your row contains a factor. Here is an example:
df_1 = data.frame(V1 = factor(11:15),
V2 = 21:25)
df_1[1,] %>% as.numeric() # you expect 11 21 but it returns
[1] 1 21
Here is another example (by default data.frame() converts characters to factors)
d...
How can I safely encode a string in Java to use as a filename?
...ey want, store the filename based on a scheme of my own choosing (eg userId_fileId) and then store the user's filename in a database table. That way you can display it back to the user, store things how you want and you don't compromise security or wipe out other files.
You can also hash the file (...
Using mixins vs components for code reuse in Facebook React
...nding fields.
Source (gist)
define(function () {
'use strict';
var _ = require('underscore');
var ValidationMixin = {
getInitialState: function () {
return {
errors: []
};
},
componentWillMount: function () {
this.assertValidatorsDefined();
},
...
How to select multiple files with ?
...ltiple="multiple"
and if you are using php then you will get the data in $_FILES and
use var_dump($_FILES) and see output and do processing
Now you can iterate over and do the rest
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How to search a specific value in all tables (PostgreSQL)?
...
How about dumping the contents of the database, then using grep?
$ pg_dump --data-only --inserts -U postgres your-db-name > a.tmp
$ grep United a.tmp
INSERT INTO countries VALUES ('US', 'United States');
INSERT INTO countries VALUES ('GB', 'United Kingdom');
The same utility, pg_dump, can...
Queries vs. Filters
... query
Query hello sam (using keyword must)
curl localhost:9200/myindex/_search?pretty -d '
{
"query": { "bool": { "must": { "match": { "msg": "hello sam" }}}}
}'
Document "Hello world! I am Sam." is assigned a higher score than "Hello world!", because the former matches both words in the qu...
What is an undefined reference/unresolved external symbol error and how do I fix it?
...Preprocessing directives are executed, macro invocations are expanded, and _Pragma unary operator expressions are executed. [SNIP]
Each source character set member in a character literal or a string literal, as well as each escape sequence and universal-character-name
in a character literal or a non...
What does the slash mean in help() output?
...meters could only be specified in the C API.
It means the key argument to __contains__ can only be passed in by position (range(5).__contains__(3)), not as a keyword argument (range(5).__contains__(key=3)), something you can do with positional arguments in pure-python functions.
Also see the Argum...