Here is the Python code for a function which factors its argument into primes. It an be called at the commandnd

line: `% python ev "factor(123456789)"`

```
```def factor(n):
"""Return list of prime factors of n. Method = trial division."""
d = 2
factors = [ ]
while n % 2 == 0:
factors.append(2)
n = n//2
d = 3
while n > 1 and d*d <= n:
if n % d == 0:
factors.append(d)
n = n//d
else:
d = d + 2
if n > 1:
factors.append(n)
return factors

zipTimer: an iPod/iPhone app for pacing piano practice, cooking, workouts, you name it.