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Checking if a string can be converted to float in Python
... ------------
print(isfloat("")) False
print(isfloat("1234567")) True
print(isfloat("NaN")) True nan is also float
print(isfloat("NaNananana BATMAN")) False
print(isfloat("123.456")) True
print(isfloat("123.E4")) ...
Is there a way to get a collection of all the Models in your Rails app?
...ase. Don't know how you can list all the classes though...
EDIT: Just for fun, I found a way to list all classes
Module.constants.select { |c| (eval c).is_a? Class }
EDIT: Finally succeeded in listing all models without looking at directories
Module.constants.select do |constant_name|
constan...
Dynamic SQL - EXEC(@SQL) versus EXEC SP_EXECUTESQL(@SQL)
...
EXEC('SELECT * FROM FOO WHERE ID=?', 123) will replace the parameter placeholder "?" with the value 123 and then execute the query, returning a result for SELECT * FROM FOO WHERE ID=123
– Peter Wone
Jun 1 '10 at 23:27
...
sed: print only matching group
...it with a 2nd grep.
# To extract \1 from /xx([0-9]+)yy/
$ echo "aa678bb xx123yy xx4yy aa42 aa9bb" | grep -Eo 'xx[0-9]+yy' | grep -Eo '[0-9]+'
123
4
# To extract \1 from /a([0-9]+)b/
$ echo "aa678bb xx123yy xx4yy aa42 aa9bb" | grep -Eo 'a[0-9]+b' | grep -Eo '[0-9]+'
678
9
...
How can I get a web site's favicon?
...ust a favourites that sits in my system tray so that I can open often-used sites/folders/files from the same place. Getting the default icons from my system for known file types isn't terribly complicated, but I don't know how to get the favicon from a website. (SO has the grey->orange stack icon in...
How can I parse a local JSON file from assets folder into a ListView?
...using below code.
and then you can simply read this string return by this function as
public String loadJSONFromAsset() {
String json = null;
try {
InputStream is = getActivity().getAssets().open("yourfilename.json");
int size = is.available();
byte[] buffer = new b...
代码块超过1.2w编译apk报错问题 - App Inventor 2 中文网 - 清泛IT社区，为创新赋能！
...y/61743accept:
*/*
accept-encoding:
gzip, deflate
accept-language:
zh-CN
connection:
keep-alive
content-length:
1101630
content-type:
text/x-gwt-rpc; charset=UTF-8
cookie:
Hm_lvt_8d287b854d737bdc880e8ddeac1b309d=1739864738,1739865332,1739865897,1741052932; HMACCOUNT=5A149F5C7832E7EE; au...
What does the “yield” keyword do?
...one, etc. And generators return... well that's where yield comes in:
def f123():
yield 1
yield 2
yield 3
for item in f123():
print item
Instead of yield statements, if you had three return statements in f123() only the first would get executed, and the function would exit. But f1...
How to search through all Git and Mercurial commits in the repository for a certain string?
...ways to do that. See "hg help revsets", esp the desc(), user(), and file() functions. There are also hg log switches for most of this behavior. In my experience, though -k/keyword() is usually the most helpful way to search for things.
– Kevin Horn
Dec 17 '12...
How can I make a horizontal ListView in Android? [duplicate]
...) There is no recycling of views. Maybe it would be possible to tack this functionality onto the scroll view, but it seems to me that it would mess with the scrolling behavior, and it would be nearly as much work as simply extending AdapterView.
– Neil Traft
O...