diff --git a/validity_check.py b/validity_check.py
new file mode 100644
index 0000000000000000000000000000000000000000..a4516f2fc641b725403d6b5d072050a8cfa0b6ea
--- /dev/null
+++ b/validity_check.py
@@ -0,0 +1,33 @@
+import csv
+import sys
+
+if __name__ == "__main__":
+
+    modified_lines = sys.argv[1]
+    author = sys.argv[2]
+    modifs = modified_lines.split('\n')
+
+    if len(modifs) != 2:
+        print("You modify wrong number of lines !")
+        exit(1)
+
+    if author not in modifs[0] and (author not in modifs[1]) :
+        print("You modify the line of another student !\n")
+        exit(1)
+
+    curr_line = modifs[1].split(',')
+
+    if len(curr_line) != 4:
+        print('You broke file format by suppressing/adding "," !\n')
+        exit(1)
+
+    prev_line = modifs[1].split(',')
+    modifs[0][0]=' '
+    modifs[0][1]=' '
+    
+    for i in range(modifs[0]):
+        if i<3 and prev_line[i] != curr_line[i] :
+            print('You modify your data !\n')
+            exit(1)
+    if(curr_line[4]) !='VU' or (curr_line[4]) !=' VU' or (curr_line[4]) !='VU ':
+        print('You have to write "VU" in the last column !\n')