Write a Python program to find all the common characters in lexicographical order from two given lower case strings. If there are no common letters print "No common characters"

from collections import Counter 
def common_chars(str1,str2): 	
	d1 = Counter(str1) 
	d2 = Counter(str2) 
	common_dict = d1 & d2 
	if len(common_dict) == 0: 
		return "No common characters."

	# list of common elements 
	common_chars = list(common_dict.elements()) 
	common_chars = sorted(common_chars) 

	return ''.join(common_chars) 

str1 = 'Python'
str2 = 'PHP'
print("Two strings: "+str1+' : '+str2)
print(common_chars(str1, str2))
str1 = 'Java'
str2 = 'PHP'
print("Two strings: "+str1+' : '+str2)
print(common_chars(str1, str2))