Hi Marissa, I really think that you could consider doing an introductory Python tutorial and then venture back into solving this problem.
Understanding concepts like data types, function syntax and loops makes all the difference in approaching programming challenges. Here is a decent and free online Python tutorial to get you going: https://www.learnpython.org/ Kind regards, Sithembewena Dube *Sent with Shift <https://tryshift.com/?utm_source=SentWithShift&utm_campaign=Sent%20with%20Shift%20Signature&utm_medium=Email%20Signature&utm_content=General%20Email%20Group>* On Tue, Aug 13, 2019 at 12:47 PM Cameron Simpson <c...@cskk.id.au> wrote: > On 12Aug2019 15:11, Marissa Russo <mruss...@u.rochester.edu> wrote: > >This is my code: > > Thank you. > > >This is the output of my updated code: > >Traceback (most recent call last): > > File "/Applications/Python 3.7/exercises .py", line 37, in <module> > > main() > > File "/Applications/Python 3.7/exercises .py", line 33, in main > > m = mean(data[0]) > > File "/Applications/Python 3.7/exercises .py", line 29, in mean > > return(sum(nums)/len(nums)) > >TypeError: unsupported operand type(s) for +: 'int' and 'str' > > Thank you for this as well, it makes things much clearer. > > So, to your code: > > >import math > > Just a remark: you're not using anything from this module. I presume you > intend to later. > > >def get_numbers(): > > print("This program will compute the mean and standard deviation") > > file1 = input("Please enter the first filename: ") > > file2 = input("Please enter the second filename: ") > > x = open(file1, "r") > > y = open(file2, "r") > > nums = x.readlines() > > nums2 = y.readlines() > > As has been mentioned in another reply, readlines() returns a list of > strings, one for each line of text in the file. > > In order to treat these as numbers you need to convert them. > > > return nums, nums2 > > > >def to_ints(strings): > > num_copy = [] > > for num in nums: > > num_copy.append(float(num)) > > return num_copy > > This returns a list of floats. You might want to rename this function to > "to_floats". Just for clarity. > > > return to_ints(nums), to_ints(nums2) > > This isn't reached. I _think_ you need to put this line at the bottom of > the get_numbers function in order to return two lists of numbers. But it > is down here, not up there. > > >def mean(nums): > > _sum = 0 > > return(sum(nums)/len(nums)) > > This is the line raising your exception. The reference to "+" is because > sum() does addition. It starts with 0 and adds the values you give it, > but you're handing it "nums". > > Presently "nums" is a list of strings, thus the addition of the initial > 0 to a str in the exception message. > > If you move your misplaced "return to_ints(nums), to_ints(nums2)" > statement up into the get_numbers function you should be better off, > because then it will return a list of numbers, not strings. > > Cheers, > Cameron Simpson <c...@cskk.id.au> > _______________________________________________ > Tutor maillist - Tutor@python.org > To unsubscribe or change subscription options: > https://mail.python.org/mailman/listinfo/tutor > _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
