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How to randomize (or permute) a dataframe rowwise and columnwise?
...ple(1:n()))
or
df2 <- sample_frac(df1, 1L)
column-wise:
df2 <- select(df1, one_of(sample(names(df1))))
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SQLAlchemy - Getting a list of tables
...te_engine('postgresql+psycopg2://root:password@localhost/
q = eng.execute('SELECT * FROM pg_catalog.pg_tables')
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How to output numbers with leading zeros in JavaScript [duplicate]
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When you post code select it and click on the {} button so it gets formatted as such.
– Shef
Sep 12 '11 at 12:05
10
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How to remove constraints from my MySQL table?
...an show the names of the foreign keys by using this query, as shown here:
SELECT CONSTRAINT_NAME FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE
WHERE REFERENCED_TABLE_SCHEMA = '<database>' AND REFERENCED_TABLE_NAME = '<table>';
Then remove the foreign key by running the before mentioned DR...
heroku - how to see all the logs
...o do from your GUI so you have to logged into your heroku account and then select your application and finally click on view logs
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Windows path in Python
...
however best practice is to use the os.path module functions that always select the correct configuration for your OS:
os.path.join(mydir, myfile)
From python 3.4 you can also use the pathlib module. This is equivelent to the above:
pathlib.Path(mydir, myfile)
or
pathlib.Path(mydir) / myfil...
Display a tooltip over a button using Windows Forms
...form designer:
Drag the ToolTip control from the Toolbox, onto the form.
Select the properties of the control you want the tool tip to appear on.
Find the property 'ToolTip on toolTip1' (the name may not be toolTip1 if you changed it's default name).
Set the text of the property to the tool tip te...
Comment the interface, implementation or both?
...mplementation with the comment from the interface when you right click and select "Document This" on the method.
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How can I scroll a web page using selenium webdriver in python?
...break
last_height = new_height
another method (thanks to Juanse) is, select an object and
label.sendKeys(Keys.PAGE_DOWN);
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How can I get a channel ID from YouTube?
...outube version is obtained very easily if you login to YouYube website and select 'My channel'
Your channel ID will be displayed on the address bar of your browser
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