CODEWITHSUNDEEP
pythonfunctionloops
T.Stimer
T.Stimer

Reputation: 325

Python beginner quest

I'm trying to learn python. I got to the point where we're learning loops "for" and got a bit of a pickle. 1st assignment was to build a function that will count all spaces, my solution was:

def count_spaces(s):
    cnt = 0
    for char in s:
        if char == " ":
            cnt = cnt+1
    return cnt

and now I'm trying to build a new function, that can accept string, char and will return the count of the specific char

for example:

print(count_char("Hello world!", " ")

and the screen will show 1 (1 space is found) this is where i got stuck:

def count_char(s, c):
    s=[...]
    num = 0
    for x in s:
        if x == x:
            num = s.count(c)
    return num

it's returning only 0 ....

please help

Upvotes: 0

Views: 372

Answers (5)

Spirit4449
Spirit4449

Reputation: 9

Remove the s=[...]. What ever the ... is, it shouldn't be there because s is an input argument and you do not want to change it.

About the code: It should only be:

count = string.count(substring)

because the str.count() implements what you want to achieve.

If you want to avoid using the built in methods and implement it yourself then you should replace

num = s.count(c) with num += 1 and the x == x (because x will always equal x and you'll be counting all the characters) with x == c like so:

def count_char(s, c):
    num = 0
    for x in s:
        if x == c:
            num += 1
    return num

Upvotes: 0

DvirH
DvirH

Reputation: 80

Remove the s=[...]. What ever the ... is, it shouldn't be there because s is an input argument and you do not want to change it.

About the code: It should only be:

count = string.count(substring)

because the str.count() implements what you want to achieve.

If you want to avoid using the built in methods and implement it yourself then you should replace

num = s.count(c) with num += 1 and the x == x (because x will always equal x and you'll be counting all the characters) with x == c like so:

def count_char(s, c):
    num = 0
    for x in s:
        if x == c:
            num += 1
    return num

Good luck and happy learning!

Upvotes: 0

Samwise
Samwise

Reputation: 71434

You're overwriting your s argument at the start of your function:

   s = [...]

which makes the rest impossible to do. Don't do that! :)

If you're allowed to use the count method (like your code is doing) you don't need the for loop at all:

def count_char(s: str, c: str) -> int:
    """The number of character c in string s."""
    return s.count(c)

If you wanted to do it without using count, you can write it exactly like your count_space function, but replace the " " with the c parameter:

def count_char(s: str, c: str) -> int:
    """The number of character c in string s."""
    cnt = 0
    for char in s:
        if char == c:
            cnt = cnt+1
    return cnt

Or you could use a for comprehension along with the sum function:

def count_char(s: str, c: str) -> int:
    """The number of character c in string s."""
    return sum(1 if char == c else 0 for char in s)

Or you could use a Counter:

from collections import Counter

def count_char(s: str, c: str) -> int:
    """The number of character c in string s."""
    return Counter(s)[c]

Upvotes: 1

zerecees
zerecees

Reputation: 699

Try this!

def count_spaces(s, c):
    cnt = 0
    for char in s:
        if char == c:
            cnt = cnt+1
    return cnt

Upvotes: 0

Marcin Orlowski
Marcin Orlowski

Reputation: 75629

I believe instead of

if x == x:

you need

if x == c:

Upvotes: 0

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