added a snippet for prime factors in python

snippets/python/s/prime-factors.md

@@ -0,0 +1,31 @@
+---
+title: Prime factors of number
+type: snippet
+language: python
+tags: [math,algorithm]
+cover: dark-leaves-3
+dateModified: 2023-05-24T00:00:00.000Z
+---
+
+Find and return the list containing prime factors of a number.
+
+- Use a `while` loop to iterate over all possible prime factors, starting with `2`.
+- If the current `factor`, exactly divides `num`, add `factor` to the `factors` list and divide `num` by `factor`. Otherwise, increment `factor` by one.
+
+```py
+def prime_factors(num):
+    factors = []
+    factor = 2
+    while (num >= 2):
+        if (num % factor == 0):
+            factors.append(factor)
+            num = num / factor
+        else:
+            factor += 1
+    return factors
+```
+
+```py
+prime_factors(12) # [2,2,3]
+prime_factors(42) # [2,3,7]
+```