What is my function missing? (python)

Question

I'm trying to create a function which prints the number of characters whose frequency is above a threshold value... (n needs to be a single non-negative number)

import urllib
txt = urllib.urlopen("http://students.informatics.unimelb.edu.au/~ivow/info1dev/mywork/info1media/data/moby.txt").read()
tally = {}
for char in txt:
 if char in tally:
 tally[char] += 1
 else:
 tally[char] = 1
char = 'b'
def freq_threshold(n):
 if tally[char] > n:
 return tally[char]
freq_threshold(3)

I want my function to return the tally of the number of times char appears in the text only if the tally is greater than my freq_threshold(n). Currently, it returns nothing..

• ZoeIngrid: the function doesn't return anything
• arshajii: In general, you should explain your exact problem in the body of your question.
• ZoeIngrid: Thanks, I have edited my post. I know there are easier ways to do what I'm trying to accomplish, but why isn't my functioning returning a number? In the URL I used b occurs 9 times...

Answer 1

The function doesn't return anything because, the count of b is lesser than the threshold. In that case, it will return None by default. Anyway, you need to print the returned value like this

print freq_threshold(3)

but if you want to display all the characters whose count is greater than the threshold, then you need to iterate the dictionary like this

def freq_threshold(n):
 return [(char, tally[char]) for char in tally if tally[char] > n]

This will print all the characters whose count is greater than 3, along with the actual count itself.

Anyway, a better way to solve your problem would be to use collections.Counter and accepting the count of the character to be checked as well as a parameter, like this

import urllib, collections
txt = urllib.urlopen("http://www.blahblahblah.com").read()
tally = collections.Counter(txt)
def freq_threshold(char, n):
 if tally[char] > n:
 return tally[char]
print freq_threshold('b', 3)

Note: You need to specify the protocol being used in the urlopen call.

• thefourtheye: @ZoeIngrid I am getting 9, are you printing the returned value, like I have shown in my answer?