M = [[0 for j in range(5)] for i in range(4)]
  for i in range(4):
     for j in range(5):
        M[i][j] = int(self.textEdit_1.toPlainText())

n = 1
  for i in range(4):
     for j in range(5):
        M[i][j] = exec('int(self.textEdit_{}.toPlainText())'.format(n))
        n += 1

n = 1
  for i in range(4):
     for j in range(5):
        M[i][j] = eval('int(self.textEdit_{}.toPlainText())'.format(n))
        n += 1

M = [[0 for j in range(5)] for i in range(4)]
n = 0
for i in range(4):
    for j in range(5):
        M[i][j] = listTextEdit[i+j+n]
    n += 4

[[1, 2, 3, 4, 5],
[6, 7, 8, 9, 10],
[11, 12, 13, 14, 15],
[16, 17, 18, 19, 20]]