python asssingment completion example using an obscene amount of generator comprehensions.

hardmode.py

# opening the csv file
def read_file(csvfile):
    file = open(csvfile, 'r')
    file.readline()
    line = file.readline()
    while line:
        line = line.strip()
        values = line.split(",")
        new_values = []
        for i, attr in enumerate(values):
            if i == 4:
                if not attr:
                    attr = 0.0
                new_values.append(float(attr))
            else:
                new_values.append(int(attr))
        yield(new_values)
        line = file.readline()


def month_data_by_year(year, table):
    output = [[] for i in range(0, 12)]
    for row in filter(lambda x: x[1] == year, table):
        output[row[2] - 1].append(row[4])
    return output


def mini(data):
    m = float('inf')
    for x in data:
        if x != 0.0:
            m = min(m, x)
    return m


def maxi(data):
    m = float('-inf')
    for x in data:
        m = max(m, x)
    return m


def avg(data):
    return sum(data) / len(data)


def std(data):
    av = avg(data)
    return (sum([(x - av)**2 for x in data]) / len(data)) ** 0.5


def corr(dx, dy):
    xhat, yhat = avg(dx), avg(dy)
    xoff, yoff = [x - xhat for x in dx], [y - yhat for y in dy]
    fact = sum(x * y for x, y in zip(xoff, yoff))
    xsq, ysq = sum((m**2 for m in xoff)), sum((m**2 for m in yoff))
    denom = (xsq**0.5) * (ysq**0.5)
    return fact / denom


def main(csvfile, year, type):
    filedata = list(read_file(csvfile))
    funcs = (mini, maxi, avg, std)
    if type == "stats":
        month_data = month_data_by_year(year, filedata)
        results = tuple(([(f(m)) for m in month_data] for f in funcs))
        return tuple(([round(v, 4) for v in d] for d in results))
    elif type == "corr":
        md1, md2 = [month_data_by_year(y, filedata) for y in year]
        r1 = tuple(([(f(m)) for m in md1] for f in funcs))
        r2 = tuple(([(f(m)) for m in md2] for f in funcs))
        return tuple((round(v, 4) for v in (corr(x, y) for x, y in zip(r1, r2))))


if __name__ == '__main__':
    print(main("sample_rainfall_data.csv", 2019, "stats"))
    print("")
    print(main("sample_rainfall_data.csv", [2018, 2019], "corr"))

sample_rainfall_data.csv