Pythonic方法生成可能的数组列表

Question

Given an array of numbers (eg [3, 5, 2]), I'm trying to generate a list of possible arrays that result from adding 1 to one entry in the array: [[4, 5, 2], [3, 6, 2], [3, 5, 3]].

I can get it done by the following, but wondering if there's a more pythonic way to get the result?

test = [3, 5, 2]
result = [t.copy() for _ in range(len(test))]
for index, _ in enumerate(result):
    result[index][index] += 1

Answer 1

Here's how to do it with a list comprehension:

test = [3, 5, 2]   
print [test[:i] + [v + 1] + test[i+1:] for i,v in enumerate(test)]

output

[[4, 5, 2], [3, 6, 2], [3, 5, 3]]

Answer 2

Here is another inline solution with list comprehension:

test = [3, 5, 2]
result = [[v+1 if i==j else v for j, v in enumerate(test)] for i in range(len(test))]

or, as noticed by PM 2Ring , you can exploit the fact that True == 1 and False == 0 :

result = [[v + (i==j) for j, v in enumerate(test)] for i in range(len(test))]