Digit factorial chains

74.py

@@ -0,0 +1,47 @@
+from math import factorial
+
+def digitFactorial(n):
+	"""Takes integer and returns the sum of the factorial of its digits"""
+	n = str(n)
+	
+	factorialSum = 0
+	
+	for digit in n:
+		digit = int(digit)
+		factorialSum += factorial(digit)
+
+	return factorialSum
+
+def isDigitFactorial(n):
+	"""Checks if number is one of the 4 loops given in prompt, method not used in solution"""
+	if n == 145 or n == 169 or n == 871 or n == 872:
+		return True
+	else:
+		return n == digitFactorial(n)
+
+def isChainDigitFactorial(n):
+	"""Returns a boolean indicating if the number is a non-repeating digit factorial"""
+	iterations = 1
+	terms = [n]
+
+	# Maximum of 50 iterations
+	while iterations < 60:
+		n = digitFactorial(n)
+
+		if n in terms:
+			return False
+		else:
+			terms.append(n)
+			iterations += 1
+	return True
+
+def main(limit):
+	"""Iterates through all integers up to limit to find non-repeating terms"""
+	numberFactorialChains = 0
+
+	for i in range(1, limit):
+		if isChainDigitFactorial(i):
+			numberFactorialChains += 1
+	return numberFactorialChains
+
+print main(1000000)