Search⌘ K
Home
Courses
Python 3: An interactive deep dive

Indenting Code

We'll cover the following...

Python functions have no explicit begin or end, and no curly braces to mark where the function code starts and stops. The only delimiter is a colon (:) and the indentation of the code itself.

Python 3.5
def approximate_size(size, a_kilobyte_is_1024_bytes=True):  #①
    if size < 0:                                            #②
        raise ValueError('number must be non-negative')     #③
                                                            #④
    multiple = 1024 if a_kilobyte_is_1024_bytes else 1000
    for suffix in SUFFIXES[multiple]:                       #⑤
        size /= multiple
        if size < multiple:
            return '{0:.1f} {1}'.format(size, suffix)
    raise ValueError('number too large')

① Code blocks are defined by their indentation. By “code block,” I mean functions, if statements, for loops, while loops, and so forth. Indenting starts a block and unindenting ends it. There are no ...