That’s more specifically a ternary operator expression than an if-then, here’s the python syntax value_when_true if condition else value_when_false Better Example: (thanks Mr. Burns) ‘Yes’ if fruit == ‘Apple’ else ‘No’ Now with assignment and contrast with if syntax fruit=”Apple” isApple = True if fruit == ‘Apple’ else False vs fruit=”Apple” isApple = False if … Read more
A mixin is a special kind of multiple inheritance. There are two main situations where mixins are used: You want to provide a lot of optional features for a class. You want to use one particular feature in a lot of different classes. For an example of number one, consider werkzeug’s request and response system. … Read more
Connecting to MYSQL with Python 2 in three steps 1 – Setting You must install a MySQL driver before doing anything. Unlike PHP, Only the SQLite driver is installed by default with Python. The most used package to do so is MySQLdb but it’s hard to install it using easy_install. Please note MySQLdb only supports … Read more
null=True sets NULL (versus NOT NULL) on the column in your DB. Blank values for Django field types such as DateTimeField or ForeignKey will be stored as NULL in the DB. blank determines whether the field will be required in forms. This includes the admin and your custom forms. If blank=True then the field will … Read more
To check the existence of a local variable: if ‘myVar’ in locals(): # myVar exists. To check the existence of a global variable: if ‘myVar’ in globals(): # myVar exists. To check if an object has an attribute: if hasattr(obj, ‘attr_name’): # obj.attr_name exists.
The property() function returns a special descriptor object: >>> property() <property object at 0x10ff07940> It is this object that has extra methods: >>> property().getter <built-in method getter of property object at 0x10ff07998> >>> property().setter <built-in method setter of property object at 0x10ff07940> >>> property().deleter <built-in method deleter of property object at 0x10ff07998> These act as … Read more
pg_config is in postgresql-devel (libpq-dev in Debian/Ubuntu, libpq-devel on Centos/Fedora/Cygwin/Babun.)
I’ve been given to understand that Python is an interpreted language… This popular meme is incorrect, or, rather, constructed upon a misunderstanding of (natural) language levels: a similar mistake would be to say “the Bible is a hardcover book”. Let me explain that simile… “The Bible” is “a book” in the sense of being a … Read more
Don’t drop, just take the rows where EPS is not NA: df = df[df[‘EPS’].notna()]
Edit 2017 As indicated in the comments and by @Alexander, currently the best method to add the values of a Series as a new column of a DataFrame could be using assign: df1 = df1.assign(e=pd.Series(np.random.randn(sLength)).values) Edit 2015 Some reported getting the SettingWithCopyWarning with this code. However, the code still runs perfectly with the current pandas … Read more