大约有 46,000 项符合查询结果（耗时：0.0681秒） [XML]
Identify if a string is a number
...
int n;
bool isNumeric = int.TryParse("123", out n);
Update As of C# 7:
var isNumeric = int.TryParse("123", out int n);
or if you don't need the number you can discard the out parameter
var isNumeric = int.TryParse("123", out _);
The var s can be replaced ...
How to determine a Python variable's type?
...
Use the type() builtin function:
>>> i = 123
>>> type(i)
<type 'int'>
>>> type(i) is int
True
>>> i = 123.456
>>> type(i)
<type 'float'>
>>> type(i) is float
True
To check if a variable is of a given type, u...
Alphabet range in Python
... 'y', 'z']
And to do it with range
>>> list(map(chr, range(97, 123))) #or list(map(chr, range(ord('a'), ord('z')+1)))
['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
Other helpful string module features:...
(Built-in) way in JavaScript to check if a string is a valid number
...rns true if the variable does NOT contain a valid number
Examples
isNaN(123) // false
isNaN('123') // false
isNaN('1e10000') // false (This translates to Infinity, which is a number)
isNaN('foo') // true
isNaN('10px') // true
Of course, you can negate this if you need...
Unable to set data attribute using jQuery Data() API
...('#changeData').click(function() {
$('#foo').data('helptext', 'Testing 123');
// $('#foo').attr('data-helptext', 'Testing 123');
console.log($('#foo').data('data-helptext'));
return false;
});
See demo
Using the Chrome DevTools Console to inspect the DOM, the $('#foo').data('helptext...
Output first 100 characters in a string
...o handle this. Here are some examples.
The formatting code '%s' converts '12345' to a string, but it's already a string.
>>> '%s' % '12345'
'12345'
'%.3s' specifies to use only the first three characters.
>>> '%.3s' % '12345'
'123'
'%.7s' says to use the first seven charac...
How can I pass a list as a command-line argument with argparse?
...'<Required> Set flag', required=True)
# Use like:
# python arg.py -l 1234 2345 3456 4567
nargs='+' takes 1 or more arguments, nargs='*' takes zero or more.
append
parser.add_argument('-l','--list', action='append', help='<Required> Set flag', required=True)
# Use like:
# python arg.p...
How to set up Android emulator proxy settings
... to use with a HTTP client:
// proxy
private static final String PROXY = "123.123.123.123";
// proxy host
private static final HttpHost PROXY_HOST = new HttpHost(PROXY, 8080);
HttpParams httpParameters = new BasicHttpParams();
DefaultHttpClient httpClient = new DefaultHttpClient(httpParameters);
ht...
Save modifications in place with awk
...ace.awk include file to invoke the extension properly like so:
$ cat file
123 abc
456 def
789 hij
$ gawk -i inplace '{print $1}' file
$ cat file
123
456
789
The variable INPLACE_SUFFIX can be used to specify the extension for a backup file:
$ gawk -i inplace -v INPLACE_SUFFIX=.bak '{print $1}'...
How to convert an int value to string in Go?
s is 'E', but what I want is "123"
9 Answers
9
...