Substrings

[OmarSinno]

The task is to find a the first string as a substring in the other string.
For example, let's say we have:
string 1 = 'bob'
string 2 = 'bobsbugsbegone'
for i in s2:
s1 == to [b]ONLY[/b] [0:2] of s2

I want to write a code that detects when there's a substring in a string and that counts how many substrings are found. (the second part is easy)

This is my code:

import sys

s1 = sys.argv[1]
s2 = sys.argv[2]
k = 0
i = 0

def substrings(s1, s2, k):
	for k in s2:
		for n in range(len(s2)):
			if k == s1[n]:
				return True
				print('s1 is a substring in s2')
			else:
				print('s1 is not a substring in s2')
				return False
		
print(substrings(s1, s2, k))

Help?

In addition to that:

Error:
(C:\Users\OmarHS\Miniconda3) c:\Users\OmarHS\Desktop\AUB\CMPS\200\ASST3>python substrings.py bob bobsbugsbegone
True

(C:\Users\OmarHS\Miniconda3) c:\Users\OmarHS\Desktop\AUB\CMPS\200\ASST3>python substrings.py bob robsbugsbegone
s1 is not a substring in s2
False

(C:\Users\OmarHS\Miniconda3) c:\Users\OmarHS\Desktop\AUB\CMPS\200\ASST3>python substrings.py bob robsbobsbegone
s1 is not a substring in s2
False

In the first try it works
In the second try it also works
In the third try, i found out that it works only if the substring is at the beginning of the second string

[metulburr]

I want to write a code that detects when there's a substring in a string and that counts how many substrings are found.

you mean like this?

Output:
>>> import re
>>> [m.start() for m in re.finditer('test', 'test test test test')]
[0, 5, 10, 15]

The length of list is the amount of occurrences, The list elements, are the string position they were found in.

[Saka]

Why don't you use s.find? The .find() function returns the index of the string the substring starts at, so for example:

"jgjbobjdeh".find("bob")

returns "3", because the substring "bob" starts at index 3. If there are multiple substrings in the string, find() will get the first one:

>>> "hfaibobgjdbobjfdks".find("bob")
4

You could easily make a function that turns the indexes each substring starts at into a list by using find and then removing the characters before the substring starts with string slicing and then search again. I'm currently in a lazy state so I'll let you make the script.

EDIT: Metalburr beat me to it and also used a much simpler and compact method haha.

[OmarSinno]

Okay, so the instructions are actually:
Write a function substring(s1,s2,k) that takes two strings and an integer index k, and returns True if the first string appears as a substring in the second at location k, and False otherwise.
Write a function how_many() that takes two strings and returns the number of times the first string ocurs in the second.

My NEW code satisfies the first, not the second:

import sys

s1 = sys.argv[1]
s2= sys.argv[2]
k = 0

def substring(s1, s2, k):
	k = s2.find(s1)
	return k

print(substring(s1,s2,k))

[nilamo]

My NEW code satisfies the first, not the second:

No it doesn't.  You ignore the k parameter, so your function will return a Truthy value when it shouldn't.
Also, the definition says you should return True/False, but right now you're returning an index that the substring starts at.  Hint: str.find() returns -1 if the substring is not found.