str = "i love python,i am learning python"

print(str.count("i")) #star 和end 为默认参数

print(str.count("i",2)) # star值为2，end值为默认参数

print(str.count("i",2,5)) #star值为2，end值为5

print(str.count("am")) #多字符统计

#!/usr/bin/python
 
str = "this is string example....wow!!!";
 
sub = "i";
print "str.count(sub, 4, 40) : ", str.count(sub, 4, 40)
sub = "wow";
print "str.count(sub) : ", str.count(sub)

str.count(sub, 4, 40) : 2
str.count(sub) : 1