AS3/Flex

Garbage Collection

1. What is reference counting?

1. when you create a reference you increment its reference counter, when it is deleted you decrement the counter.

2. Advantages/Disadvantages of reference counting?

1. (pro) simple methodology for knowing when to garbage collect
2. (pro) doesn't carry huge CPU overhead
3. (con) not optimal for circular referencing
   1. circular referencing is the situation when objects cross-reference each other (directory or indirectly)

Python

0. Does spacing and indentation matter in Python?

1. what are some common types of collections?

-- tuple, list, dict, set

What's the difference between tuple, list, dict, set?

What can be types can be used as keys in a dictionary? (any immutable type)

How do you slice a list? How do you remove something from a list? dictionary?

2. what's the type of 'x'?

x = (1)

3. what is tuple unpacking and how do you do it?

4. Which option gives the output "01234"?

a) [num for num in xrange(5)]

b) .join([num for num in xrange(5)])

c) .join([num for num in xrange(5)])

d) .join(['num' for num in xrange(5)])

5) how do you read the lines of a file?

6) which python library would you use to get the absolute path of a directory?

-- os.path (specifically call the os.path.abspath function)

7) whats the syntax for handling a variable list of arguments? key/value arguments?

-- *args -- **kwargs

8) Does python provide exception handling? how do you handle an exception?

-- can you handle more than one type of exception in a single "except" statement? -- how do you handle all exceptions?

9) what are decorators?

-- dynamically alter the functionality of a function,method or class without using subclasses or changing source code)

def audit(f, *args, **kwargs):

def new_f(*args, **kwargs):

print 'before', f.name

f(*args, **kwargs) print 'after', f.name

new_f.name = f.name return new_f

@audit def greet(name):

print 'Hello', name

9) Do you test python code? how? does python provide anything to help unit test your code?

-- python includes the unittest library (aka PyUnit?) -- has test case (unittest.TestCase?) and test suites, etc -- just like JUnit

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Django

1) have you used django? any other python web frameworks? compare likes/dislikes

-- what are some of the features it provides?

ORM, automatic admin interface, "pretty URL's", template system, caching system, internationalization

2) What is MVC? How does Django do MVC?

-- MTV (model-template-view),

-- why "view" and not "controller"?

view describes which data you see, not how you see it)

3) What does the Django admin functionality provide?

-- can create users, groups -- create, edit, delete instances of your models (do have to register them with the "admin")

4) What is ORM? How does Django provide ORM?

-- ORM (object relational mapper) provides a database abstraction API -- models all have a "Manager" called "objects"

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Database

1) If you have a many-to-many relationship, how many tables would you have?

MySQL

1) From the command line, how do you list the databases in a MySQL instance?

show databases;

2) From the command line, how do you select a DB to use?

use <db name>;

3) From the command line, how do you list the tables in the selected database?

show tables;

4) From the command line, how do you list the details of a table (i.e. column names, types, etc)?

describe <table name>;

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Troubleshooting

1. User is getting an error, "can't connect to <DB type here>" message, what do you do first?