摆脱嵌套(不必要？)for-循环

def process_row(row):
    for item in row:
        # 处理每一行的元素
        pass

def main():
    data = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
    for row in data:
        process_row(row)

data = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
flattened_data = [item for row in data for item in row]

from functools import reduce

data = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
flattened_data = reduce(lambda acc, row: acc + row, data, [])

import numpy as np

data = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
flattened_data = data.flatten()

data = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
total = 0
for row in data:
    for item in row:
        total += item
print(total)  # 输出 45

from functools import reduce

data = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
total = reduce(lambda acc, row: acc + sum(row), data, 0)
print(total)  # 输出 45