Programs for correcting students exercises Add new snippet

files.py

#!/bin/env python3
import os
import hashlib

def hashfile(afile, hasher, blocksize=65536):
    buf = afile.read(blocksize)
    while len(buf) > 0:
        hasher.update(buf)
        buf = afile.read(blocksize)
    return hasher.digest()

## read the directory updating all files the students turned in
def read_directory():
    path = os.getcwd()
    filePaths = []
    root = [x[0] for x in os.walk(path)]
    dirs = [x[1] for x in os.walk(path)][0]
    files = [x[2] for x in os.walk(path)]
    del files[0] 
    del root[0]

    for i in range(len(dirs)):
        if dirs[i] == '__pycache__':
            continue
        for f in files[i]:
            filePaths.append(os.path.join(root[i],f))
    return filePaths

def check_hashes(files):
    hashes = dict()
    for f in files:
        hashValue = hashfile(open(f, 'rb'), hashlib.md5())
        if hashValue in hashes:
            print("%s !!! %s" %(hashes[hashValue], f))
        else:
            hashes[hashValue] = f


def get_file_types(files):
    types = set()
    for f in files:
        types.add(f.split('.')[-1])
    for t in types:
        print(t)
def main():
    files = read_directory()
    print('file types found:')
    get_file_types(files)
    print('hash collisions:')
    check_hashes(files)

if __name__ == "__main__":
    main()

pp_correcting.py

#!/bin/env python3
import os
import sys
import subprocess 

## global storage for student records, the path for the csv and the currently opened file
STUDENTS = []
PATH_TO_CSV = os.path.join(os.getcwd(), 'points.csv')
OPEN_FILE = None
SAVE_AFTER_NO_CORRECTIONS = 5 # use negative value to disable


## for storing students data
class Student:
    def __init__(self, identifier):
        self.identifier = identifier 
        self.points = '---'
        self.comment = ''
        self.filepaths = []

    def set_points(self, points):
        self.points = points

    def append_file(self, filepath):
        self.filepaths.append(filepath)

    def __str__(self):
        return "%s;%s;%s\n" % (self.identifier, self.points, self.comment)

    def add_comment(self, comment):
        self.comment = comment.replace(';', '-')

## read the directory updating all files the students turned in
def read_directory():
    global STUDENTS
    path = os.getcwd()

    root = [x[0] for x in os.walk(path)]
    dirs = [x[1] for x in os.walk(path)][0]
    files = [x[2] for x in os.walk(path)]
    del files[0] 
    del root[0]

    for i in range(len(dirs)):
        if dirs[i] == '__pycache__':
            continue
        s = Student(dirs[i]) 
        for f in files[i]:
            s.append_file(os.path.join(root[i],f))
        STUDENTS.append(s)

    STUDENTS= sorted(STUDENTS, key=lambda student: student.identifier)

## read the csv file updating students records
def read_csv_file():
    global STUDENTS
    csv_file = open(PATH_TO_CSV, 'r')
    counter = 0
    notifiy = False
    for line in csv_file:
        student = STUDENTS[counter]
        data = line.split(';')
        if data[0] == student.identifier:
            student.set_points(data[1])
            student.add_comment(data[2].rstrip())
        else:
            notifiy = True
        counter += 1
    if notifiy:
        print('The csv does NOT match the downloads, aborting')
        sys.exit(-1) 

## dump all students into the csv
def dump_csv():
    csv_file = open(PATH_TO_CSV, 'w')
    for student in STUDENTS:
        csv_file.write("%s" % student)
    csv_file.close()

## opens files the students turned in, this the only OS dependent part, feel free to change it
def open_file(filepath):
    global OPEN_FILE
    if filepath[-3:].lower() == 'pdf':
        OPEN_FILE = subprocess.Popen(['zathura', filepath], stdout=subprocess.DEVNULL,
                stderr=subprocess.DEVNULL)
        return True
    return False

## start correcting one student
def correct_student(index):
    global STUDENTS
    global OPEN_FILE
    student = STUDENTS[index]
    print('Correcting student no. %d' % index)
    file_to_open = ''
    if len(student.filepaths) > 1:
        for i in range(len(student.filepaths)):
            print('%d: %s' % (i, student.filepaths[i]))
        choosen_file = ''
        while True:
            try:
                usr_input = input('Which file do you want to open?')
                if usr_input == 'q':
                    return False
                choosen_file = int(usr_input)
                if choosen_file >= 0 and choosen_file < len(student.filepaths):
                    break
            except ValueError:
                pass
            print('You have to input a valid number!')
        file_to_open = student.filepaths[choosen_file]
    else:
        file_to_open = student.filepaths[0]
    if not open_file(file_to_open):
        student.points = '---'
        student.add_comment('files could not be opened')
        return True
    while True:
        try:
            usr_input = input('Input the number of points:')
            if usr_input == 'q':
                return False
            elif usr_input == '-':
                if OPEN_FILE is not None:
                    OPEN_FILE.kill()
                return True
            points = int(usr_input)
            if points >= 0:
                student.set_points(points)
                comment = input('If you want you can add a comment:\n')
                if comment != '':
                    student.add_comment(comment)
                if OPEN_FILE is not None:
                    OPEN_FILE.kill()
                return True
        except ValueError:
            pass
        print('You have to input a valid number!')

## updates the csv and exits
def save_and_exit():
    global OPEN_FILE
    if OPEN_FILE is not None:
        OPEN_FILE.kill()
    dump_csv()
    sys.exit(0)

## start correcting
## you can choose a number to start with and the walk to the end :-)
## any student where the points entry in the csv is not '---' will be skipped!
## 'q' will exit the program
def correct():
    global STUDENTS
    starting_id = ''
    while True:
        starting_id = input('Enter the id to start with (0-%d):' % (len(STUDENTS) - 1))
        try:
            starting_id = int(starting_id)
            break
        except ValueError:
            if starting_id == 'q':
                save_and_exit()
        print('wrong input, try again')
    counter = 0
    for i in range(starting_id, len(STUDENTS)):
        if STUDENTS[i].points != '---':
            continue
        if not correct_student(i):
            save_and_exit()
        counter += 1
        if SAVE_AFTER_NO_CORRECTIONS == counter:
            dump_csv()
            counter = 0
    print('You reached the last student, saving and exiting')
    save_and_exit()

def main():
    read_directory()
    read_csv_file()
    correct()

if __name__ == "__main__":
    main()