Syntax etc.

Syntax: Indentation (1)

Blocks and Indentation

• Statements that end with a ‘:’ introduce a block

• Blocks are indented

• End of a block is end of indentation

• No explicit block delimiters (like ‘{’, ‘BEGIN’, …)

• Indentation is not only Coding Style, but also Syntax*

Careful, you experienced programmers!

• New bug type: Indentation Bug

Syntax: Indentation (2)

i = 0
while i < 42:
    print('Still not an answer: '+str(i))
    i = i+1
print('The answer is: '+str(i))

Keep in mind …

• Indentation must be consistent within one block

• … can be mixed otherwise

• Tune your editor’s knobs accordingly!

Syntax: Statements and Lines

Newline ends a statement …

answer = 42

Except … Multiline statements

answer = str(42) + \
     ', but only most of the time'

Braces	Brackets	Fun
print( "Hello", "World")	message = [ "Hello", "World"]	message = ( "Hello " + "World")

Comments vs. Documentation

As in many other script languages …

# this is a very important comment, which is
# definitely worth a read

Docstrings (slightly off-topic)

• First string in a function, module, class, or method

• Tools to generate documentation from it

def do_something(some_number):
    """ Doing something with a number """
    # some code here ...

>>> print(do_something.__doc__)
Doing something with a number