Python returns all substrings of a string (tips)

1. A custom function can return a list of substrings in order.

def restr(s):
    results = []
    # x + 1 表示子串的长度
    for x in range(len(s)):
        # i 表示滑窗长度
        for i in range(len(s) - x):
            results.append(s[i:i + x + 1])
    return results

print(restr("flow"))

The result is:

2. It can also be solved in one line, which is equivalent to the custom function above.

>>> s = 'flow'
>>> [s[i:i + x + 1] for x in range(len(s)) for i in range(len(s) - x)]
['f', 'l', 'o', 'w', 'fl', 'lo', 'ow', 'flo', 'low', 'flow']