CODEWITHSUNDEEP
pythonloopspython-2.7divisiondivide-by-zero
AEA
AEA

Reputation: 223

How to avoid division by zero error, when performing calculations on parsed xml data

please be kind with your answers I have been coding now for 10 days. I am having trouble with performing loops in my code, but I am fairly certain this is because I am getting a traceback.

I parse an xml file obtained from a url, using the following code: 

pattern4 = re.compile('title=\'Naps posted: (.*) Winners:')
pattern5 = re.compile('Winners: (.*)\'><img src=')

for row in xmlload1['rows']:
    cell = row["cell"]

##### defining the Keys (key is the area from which data is pulled in the XML) for use   in the pattern finding/regex
    user_delimiter = cell['username']
    selection_delimiter = cell['race_horse']

##### the use of the float here is to make sure the result of the strike rate calculations returns as a decimal, otherwise python 2 rounds to the nearest integer! 
    user_numberofselections = float(re.findall(pattern4, user_delimiter)[0])
    user_numberofwinners = float(re.findall(pattern5, user_delimiter)[0])

    strikeratecalc1 = user_numberofwinners/user_numberofselections
    strikeratecalc2 = strikeratecalc1*100

##### Printing the results of the code at hand

    print "number of selections = ",user_numberofselections
    print "number of winners = ",user_numberofwinners
    print "Strike rate = ",strikeratecalc2,"%"
    print ""

getData()

This code with the rest of the code returns: 

number of selections =  112.0
number of winners =  21.0
Strike rate =  18.75 %

number of selections =  146.0
number of winners =  21.0
Strike rate =  14.3835616438 %

number of selections =  163.0
number of winners =  55.0
Strike rate =  33.7423312883 %

Now the results of this xmlload suggest that there is only three users to parse however there is a 4th whos data would read 

number of selections =  0
number of winners =  0
Strike rate =  0

for my purposes it is not necessary to pull in user stat's for those with no track record, how do i make the code either skip users with 0 selections or at least make it so that the division by zero error doesn't affect the ability of the code to run in a loop?

Kind regards!

Upvotes: 0

Views: 9787

Answers (1)

Achrome
Achrome

Reputation: 7821

Just use a continue when you find a 0.

user_numberofwinners = float(re.findall(pattern5, user_delimiter)[0])

# if the number of winners is 0, go to the next row to avoid division by 0
if user_numberofwinners == 0.0 : continue;

Upvotes: 6

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