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What exactly does Perl's “bless” do?
...e is stored in $obj (associated by bless with package "Class"), then $obj->foo(@args) will call a subroutine foo and pass as first argument the reference $obj followed by the rest of the arguments (@args). The subroutine should be defined in package "Class". If there is no subroutine foo in packa...
How do you append to a file in Python?
...d read (but all writes will still be at the end of the file!).
Example:
>>> with open('test1','wb') as f:
f.write('test')
>>> with open('test1','ab') as f:
f.write('koko')
>>> with open('test1','rb') as f:
f.read()
'testkoko'
Note: Using 'a' is ...
Migration: Cannot add foreign key constraint
...up()
{
Schema::create('priorities', function($table) {
$table->increments('id', true);
$table->integer('user_id')->unsigned();
$table->string('priority_name');
$table->smallInteger('rank');
$table->text('class');
$table->timest...
Is there a RegExp.escape function in Javascript?
...
Standard arguments against augmenting built-in objects apply here, no? What happens if a future version of ECMAScript provides a RegExp.escape whose implementation differs from yours? Wouldn't it be better for this function not to be attached to anything?
...
Change column type from string to float in Pandas
...
The input to to_numeric() is a Series or a single column of a DataFrame.
>>> s = pd.Series(["8", 6, "7.5", 3, "0.9"]) # mixed string and numeric values
>>> s
0 8
1 6
2 7.5
3 3
4 0.9
dtype: object
>>> pd.to_numeric(s) # convert everything to float val...
What is the canonical way to trim a string in Ruby without creating a new string?
...lace.
Hope this helps.
Update: This is output from irb to demonstrate:
>> @title = "abc"
=> "abc"
>> @title.strip!
=> nil
>> @title
=> "abc"
>> @title = " abc "
=> " abc "
>> @title.strip!
=> "abc"
>> @title
=> "abc"
...
Pandas - Get first row value of a given column
...ct dtype. So
selecting columns is a bit faster than selecting rows. Thus, although
df_test.iloc[0]['Btime'] works, df_test['Btime'].iloc[0] is a little bit
more efficient.
There is a big difference between the two when it comes to assignment.
df_test['Btime'].iloc[0] = x affects df_test, but df_tes...
How to add an integer to each element in a list?
...
>>> mylist = [1,2,3]
>>> [x+1 for x in mylist]
[2, 3, 4]
>>>
list-comprehensions python.
share
|
...
What's the absurd function in Data.Void useful for?
...ase is to handle impossible paths. For example
simple :: Either Void a -> a
simple (Left x) = absurd x
simple (Right y) = y
This turns out to be somewhat useful. Consider a simple type for Pipes
data Pipe a b r
= Pure r
| Await (a -> Pipe a b r)
| Yield !b (Pipe a b r)
this is a ...
Create list of single item repeated N times
I want to create a series of lists, all of varying lengths. Each list will contain the same element e , repeated n times (where n = length of the list).
...