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What are the rules for evaluation order in Java?
...at does not mean that the b=0 runs first! The rules of precedence say that indexing is higher precedence than assignment, but that does not mean that the indexer runs before the rightmost assignment.
(UPDATE: An earlier version of this answer had some small and practically unimportant omissions in ...
MySQL Error 1215: Cannot add foreign key constraint
...
Also possible failure is absence of index on target field.
– Paul T. Rawkeen
Jun 9 '16 at 9:23
1
...
Case-insensitive search in Rails model
...validates :name, presence: true, uniqueness: {case_sensitive: false}
the index (answer from Case-insensitive unique index in Rails/ActiveRecord?):
execute "CREATE UNIQUE INDEX index_products_on_lower_name ON products USING btree (lower(name));"
I wish there was a more beautiful way to do the fi...
How do I include a file over 2 directories back?
...nclude a file that is more than 2 directories back. I know you can use ../index.php to include a file that is 2 directories back, but how do you do it for 3 directories back?
Does this make sense?
I tried .../index.php but it isn't working.
...
Intelligent way of removing items from a List while enumerating in C#
...from it then I suggest simply using a while loop instead of a foreach
var index = 0;
while (index < myList.Count) {
if (someCondition(myList[index])) {
myList.RemoveAt(index);
} else {
index++;
}
}
share
...
How to display pandas DataFrame of floats using a format string for columns?
...= pd.DataFrame([123.4567, 234.5678, 345.6789, 456.7890],
index=['foo','bar','baz','quux'],
columns=['cost'])
print(df)
yields
cost
foo $123.46
bar $234.57
baz $345.68
quux $456.79
but this only works if you want every float to be formatted with a d...
Keep file in a Git repo, but don't track changes
... you do not want to be tracked and use the following command:
git update-index --assume-unchanged FILE_NAME
and if you want to track the changes again use this command:
git update-index --no-assume-unchanged FILE_NAME
git-update-index documentation
...
Python pandas: fill a dataframe row by row
...of the elements)
In [7]: df = pandas.DataFrame(columns=['a','b','c','d'], index=['x','y','z'])
In [8]: df.loc['y'] = pandas.Series({'a':1, 'b':5, 'c':2, 'd':3})
In [9]: df
Out[9]:
a b c d
x NaN NaN NaN NaN
y 1 5 2 3
z NaN NaN NaN NaN
...
Accessing elements of Python dictionary by index
...alues() on a dict to get a list of the inner dicts and thus access them by index.
>>> mydict = {
... 'Apple': {'American':'16', 'Mexican':10, 'Chinese':5},
... 'Grapes':{'Arabian':'25','Indian':'20'} }
>>>mylist = list(mydict.values())
>>>mylist[0]
{'American':'16', '...
Adding div element to body or document in JavaScript
... += '<div style="position:absolute;width:100%;height:100%;opacity:0.3;z-index:100;background:#000;"></div>';
instead of
document.body.innerHTML = '<div style="position:absolute;width:100%;height:100%;opacity:0.3;z-index:100;background:#000;"></div>';
Edit:-
Ideally you ...