替换矩阵中的符号

matrix = [
    ['a', 'b', 'c'],
    ['d', 'e', 'f'],
    ['g', 'h', 'i']
]

def replace_symbols(matrix, old_symbol, new_symbol):
    for i in range(len(matrix)):
        for j in range(len(matrix[i])):
            if matrix[i][j] == old_symbol:
                matrix[i][j] = new_symbol
    return matrix

# 示例矩阵
matrix = [
    ['a', 'b', 'c'],
    ['d', 'e', 'f'],
    ['g', 'h', 'i']
]

# 替换 'a' 为 'x'
new_matrix = replace_symbols(matrix, 'a', 'x')
print(new_matrix)

[
    ['x', 'b', 'c'],
    ['d', 'e', 'f'],
    ['g', 'h', 'i']
]