Question

这是我的IT课程，我试图找到每一行的总和。它是一个神奇的方形程序。当我运行它时，它说int对象不可迭代。老师也想要函数的头像def rowSum（matrix，rowNum），但我不明白为什么需要rowNum。该函数应该能够计算任何大小矩阵的每一行的总和。我也不能使用numpy和enumarate，因为我们还没有在课堂上讨论它。

Matrix txt文件：

1 4
3 2

这是代码

def main():
    filNam = "matrix1.txt"
    matrix = (readMatrix(filNam))
    print(eachNumPresent(matrix))
    print(rowSum(matrix))

def readMatrix(filNam):
    matrixFile = open(filNam, "r")
    line = matrixFile.readline()
    for line in matrixFile:
        line = line.split()
    return line
    matrixFile.close()

def eachNumPresent(matrix):
    if len(matrix) % 2 == 0:
        return True
    else:
        print("Not enough numbers")

def rowSum(matrix, rowNum):
    for line in matrix:
        return(sum(int(line)))

main()

Answer 1

这个怎么样，它假定当你想要第一行时，你输入'0'如果你想要第二行你输入'1'等等......很容易改变。

def main():
    fn = "matrix1.txt"
    matrix = readMatrix(fn)
    n = int(input("Enter row number: "))
    rowSum(matrix, n)

def readMatrix(fn):
    matrix = []
    with open(fn) as f: # a with block will auto close your file after the statements within it
        for line in f:
            line = line.strip() # strip off any trailing whitespace(including '\n')
            matrix.append(line.split()) 
    return matrix

def rowSum(matrix, rowNum):
    result = sum(int(i) for i in matrix[rowNum])
    print("The sum of row {} = {}".format(rowNum, result))

main()

示例输出：

The sum of row 1 = 5

编辑：

计算列的总和：

def main():
    fn = "matrix1.txt"
    matrix = readMatrix(fn)
    n = int(input("Enter col number: "))
    colSum(matrix, n)

def readMatrix(fn):
    matrix = []
    with open(fn) as f: # a with block will auto close your file after the statements within it
        for line in f:
            line = line.strip() # strip off any trailing whitespace(including '\n')
            matrix.append(line.split()) 
    return matrix

def colSum(matrix, colNum):
    result = sum(int(row[colNum]) for row in matrix)
    print("The sum of col {} = {}".format(colNum, result))

main()

Answer 2

你没有迭代正确的序列，你使用“readline”而不是“readlines”，它只读取矩阵的一行，而不是整个文件。你想要做的是读取所有行，并将这些行转换为列表，因此你可以使用sum（）。请注意，在拆分之后，您需要确保将生成的字符串转换为int。通过它，您可以将矩阵形成为列表列表（格式为[[1,2]，[3,4]]），然后您可以将行号（从零开始，但可以调整）传递给rowSum方法（这就是为什么你的老师为你提供了这种格式的原因）

查看更正示例中的差异（我在不同的操作中列出了转换的步骤，但您实际上可以重构该代码以在更少的行中完成）：

def main():
    filNam = "matrix1.txt"
    matrix = (readMatrix(filNam))
    print(eachNumPresent(matrix))
    print(rowSum(matrix, 0))

def readMatrix(filNam):
    with open(filNam, 'r') as matrixFile:
        matrix = []
        lines = matrixFile.readlines()
        for line in lines:
            items = line.split()
            numbers = [int(item) for item in items]
            print numbers
            matrix.append(numbers)
        return matrix

def eachNumPresent(matrix):
    if len(matrix) % 2 == 0:
        return True
    else:
        print("Not enough numbers")

def rowSum(matrix, rowNum):
    for line in matrix:
        return(sum(line))

main()

如果您需要任何澄清，请告诉我......希望它有所帮助！

Answer 3

1.你可以学习大熊猫

2.您的代码有错误，这是我的代码

def main():
    filNam = "matrix1.txt"
    rowNum, matrix = (readMatrix(filNam))
    print(eachNumPresent(rowNum))
    rowSum(matrix)

def readMatrix(filNam):
    matrix_list = []
    total_num = 0
    with open(filNam, 'r') as matrixFile:
        for line in matrixFile.readlines():
            line = line.split()
            line = [int(i) for i in line]
            matrix_list.append(line)
            total_num += len(line)
    return total_num, matrix_list

def eachNumPresent(num):
    if num % 2 == 0:
        return True
    else:
        print("Not enough numbers")

def rowSum(matrix):
    for row in matrix:
        print sum(row)

main()

出：

True
5
5

Python从文件中读取矩阵

3 个答案: