Relying on the behaviour of empty container in conditional statements

[horizon5]

Hi,

my collegues and I recently held a coding style review.
All of the code we produced is used in house on a commerical project.
One of the minor issues I raised was the common idiom of specifing:

<pre>
if len(x) > 0:
    do_something()
</pre>
Instead of using the language-defined bahviour, as stated by PEP8:

<pre>
    - For sequences, (strings, lists, tuples), use the fact that empty
      sequences are false.

      Yes: if not seq:
           if seq:

      No: if len(seq)
          if not len(seq)
</pre>

Without wishing to start a flame war, what are other's opinions on
this, is using "len" safer? If so why?

Arguments that have been presented for using <code>len(x) > 0</code> to
test emptiness of a container include:
  - It's safer
  - Not relying on weird behaviour of the language
  - Explicit is better than implicit (as stated by 'this' module, Zen
of Python)

My own feeling is that I am willing to work with the behaviours defined
by Python, and treat the use of len in these cases as excessive
duplication (this is however, quite a minor point i agree).

Note that I have much more experience with the language (6-7 years),
whilst the majority of my collegues have about 1-2 years experience.