entrada = str(input().lower())
replace = "mem".lower()
find = entrada.lower()
count = 0
while (entrada.find(replace) != -1):
entrada = entrada.replace(replace, "", 1)
count +=1
print(count)
No count,list or lambda can be used. I'm suposed to make a program that receives a lower string from the user then finds, counts and print the number of times a substring appeared. But I'm having problems with overlapping strings.
example: string is memem, the expected exit is 2
One way to do this is to use the second argument of str.find which indicates an optional index to start searching for the substring within a string.
From the docs:
str.find(sub[, start[, end]])¶ Return the lowest index in the string where substring sub is found, such that sub is contained in the slice s[start:end]. Optional arguments start and end are interpreted as in slice notation. Return -1 if sub is not found.
So if we keep track of the last_index found in a variable, we can simply start the search for the substring again in the next possible index. Expressed in code, this is the expression
last_index + 1. If last_index is ever -1, we stop searching for the substring and output our count:
mystr = 'memem'
mysubstr = 'mem'
count = 0
last_index = -1
while True:
last_index = mystr.find(mysubstr, last_index + 1)
if last_index == -1:
break
count += 1
print(count)
You could use
i = 0
while True:
i = entrada.find(replace, i) + 1
if i:
count += 1
else:
break
This will then find replace in entrada, increment the count, find replace in entrada[i+1:] where i is the start of the previous match, increment the count, and repeat forever.
AttributeError. Also my question - the user provides both the substring and string?