Plagiarism Checker

# OS Module for loading paths of textfiles. TfidfVectorizer to perform word embedding on the textual data and cosine similarity to compute the plagiarism.
import os
from sklearn.feature_extraction.text import TfidfVectorizer
from sklearn.metrics.pairwise import cosine_similarity
student_files = [doc for doc in os.listdir() if doc.endswith('.txt')]
student_notes = [open(File).read() for File in student_files]
# Two lambda functions, one to convert the text to arrays of numbers and the other one to compute the similarity between them.
# http://www.pillalamarri.in/python/plagiarism-checker/

def vectorize(Text): return TfidfVectorizer().fit_transform(Text).toarray()


def similarity(doc1, doc2): return cosine_similarity([doc1, doc2])


# Vectorize the Textual Data
vectors = vectorize(student_notes)
s_vectors = list(zip(student_files, vectors))

# computing the similarity among students


def check_plagiarism():
    plagiarism_results = set()
    global s_vectors
    for student_a, text_vector_a in s_vectors:
        new_vectors = s_vectors.copy()
        current_index = new_vectors.index((student_a, text_vector_a))
        del new_vectors[current_index]
        for student_b, text_vector_b in new_vectors:
            sim_score = similarity(text_vector_a, text_vector_b)[0][1]
            student_pair = sorted((student_a, student_b))
            score = (student_pair[0], student_pair[1], sim_score)
            plagiarism_results.add(score)
    return plagiarism_results
# http://www.pillalamarri.in/python/plagiarism-checker/

for data in check_plagiarism():
    print(data)