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[Solved] Type: unsupported operand type(s) for -: ‘list’ and ‘list’

Hello Guys, How are you all? Hope You all Are Fine. Today I get the following error Type: unsupported operand type(s) for -: ‘list’ and ‘list’ in python. So Here I am Explain to you all the possible solutions here.

Without wasting your time, Let’s start This Article to Solve This Error.

How Type: unsupported operand type(s) for -: ‘list’ and ‘list’ Error Occurs?

Today I get the following error Type: unsupported operand type(s) for -: ‘list’ and ‘list’ in python.

How To Solve Type: unsupported operand type(s) for -: ‘list’ and ‘list’ Error ?

  1. How To Solve Type: unsupported operand type(s) for -: 'list' and 'list' Error ?

    To Solve Type: unsupported operand type(s) for -: 'list' and 'list' Error You can also use list comprehension, but it will require changing code in the function:

  2. Type: unsupported operand type(s) for -: 'list' and 'list'

    To Solve Type: unsupported operand type(s) for -: 'list' and 'list' Error You can also use list comprehension, but it will require changing code in the function:

Solution 1


You can’t subtract a list from a list.

>>> [3, 7] - [1, 2]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unsupported operand type(s) for -: 'list' and 'list'

Simple way to do it is using numpy:

>>> import numpy as np
>>> np.array([3, 7]) - np.array([1, 2])
array([2, 5])

You can also use list comprehension, but it will require changing code in the function:

>>> [a - b for a, b in zip([3, 7], [1, 2])]
[2, 5]

>>> import numpy as np
>>>
>>> def Naive_Gauss(Array,b):
...     n = len(Array)
...     for column in xrange(n-1):
...         for row in xrange(column+1, n):
...             xmult = Array[row][column] / Array[column][column]
...             Array[row][column] = xmult
...             #print Array[row][col]
...             for col in xrange(0, n):
...                 Array[row][col] = Array[row][col] - xmult*Array[column][col]
...             b[row] = b[row]-xmult*b[column]
...     print Array
...     print b
...     return Array, b  # <--- Without this, the function will return `None`.
...
>>> print Naive_Gauss(np.array([[2,3],[4,5]]),
...                   np.array([[6],[7]]))
[[ 2  3]
 [-2 -1]]
[[ 6]
 [-5]]
(array([[ 2,  3],
       [-2, -1]]), array([[ 6],
       [-5]]))

Solution 2

Use Set in Python

>>> a = [2,4]
>>> b = [1,4,3]
>>> set(a) - set(b)
set([2])

Summery

It’s all About this issue. Hope all solution helped you a lot. Comment below Your thoughts and your queries. Also, Comment below which solution worked for you? Thank You.

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