everytime i run my code it overwrites to first line of output.txt. How can i make it so it writes to a new line every time?
def calculate_averages(input_file_name, output_file_name): with open(input_file_name) as f: reader = csv.reader(f) for row in reader: name = row[0] these_grades = list() for grade in row[1:]: these_grades.append(int(grade)) with open(output_file_name, 'w') as external_file: print(name, mean(these_grades), end='n', file=external_file) external_file.close()
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Answer
This is happening because you are reopening your file in “w” mode for each row, which will overwrite your file. You can open the file outside of the for loop to avoid this behaviour:
import numpy as np import csv def calculate_averages(input_file_name, output_file_name): with open(input_file_name) as f: reader = csv.reader(f) with open(output_file_name, 'w') as external_file: for row in reader: name = row[0] mean_of_grades = np.mean([int(x) for x in row[1:]]) external_file.write(f"{name} {mean_of_grades}n")