Python: minimum not defined

Question

I was using this code to seperate max and min values and it worked for the first few times. but afterwards when debugging it threw up Exception Unhandled: name "minimum" is not defined. Any bit of help would be much appreciated, the code was not written by myself but my friend cant help me out until monday and i was hoping to finish up with what i was doing before then.

import csv


# Function to split list l in to n-sized chunks
def chunks(l, n):
    for i in range(0, len(l), n):
        yield l[i:i + n]


# Imports the .csv file
# Note: File must be in same directory as script and named 'data.csv' unless the line below is changed
with open('data.csv') as csvfilein:
    datareader = csv.reader(csvfilein, delimiter=',', quotechar='|')
    data = []
    for row in datareader:
        data.append(row)

data_intervals = chunks(data, 10) # Split array 'data' into intervals of 10 tuples

# CSV writeback to file 'out.csv' in the same folder as script
with open('out.csv', 'wt') as csvfileout:
    # Initialize writer
    datawriter = csv.writer(csvfileout, delimiter=',', quoting=csv.QUOTE_MINIMAL, lineterminator='\n')

    # Write headings to file
    datawriter.writerow(['Interval #', '', 'Min force (kN)', 'Distance (mm)', '', 'Max force (kN)', 'Distance (mm)'])

    interval_count = 1  # Current interval count

    for current_interval in data_intervals: # Iterate through each interval

        # Calculate the min and max values in the current interval based on the SECOND value (force, not distance)
        # This is what the lambda function is for
        try:
            minimum = min(current_interval, key=lambda t: int(t[1]))
            maximum = max(current_interval, key=lambda t: int(t[1]))
        except ValueError:
            pass  # Code was throwing errors for blank entries, this just skips them

        # Write the values for the current interval
        datawriter.writerow([interval_count, '', minimum[1], minimum[0], '', maximum[1], maximum[0]])

        interval_count += 1  # Update count

If exception occurs you're not creating variable `minimum` and `maximum` thus you get error when you try to access it. — Filip Młynarski, Jan 19 '19 at 17:27

score 0 · Accepted Answer · answered Jan 19 '19 at 17:29

You use a try-except block to handle reading blank entries, but then go on to attempt to handle them. This handling code should also be inside the try block:

# Calculate the min and max values in the current interval based on the SECOND value (force, not distance)
# This is what the lambda function is for
try:
    minimum = min(current_interval, key=lambda t: int(t[1]))
    maximum = max(current_interval, key=lambda t: int(t[1]))

    # This was originally outside the "try" block
    # Write the values for the current interval
    datawriter.writerow([interval_count, '', minimum[1], minimum[0], '', maximum[1], maximum[0]])

    interval_count += 1  # Update count

except ValueError:
    pass  # Code was throwing errors for blank entries, this just skips them

Python: minimum not defined

1 Answers1