在 Python 中组合单个元组以形成一个列表

Question

我正在学习编码，但我被困住了。我试图定义一个函数，它从文件中读取数据并将其转换为单个列表，列表中的每个项目都是具有整数、浮点数和字符的元组。

def reader(a_file):
    file = open(a_file, "r")
    listy = file.readlines()
    # print(listy)
    # print(type(listy))
    for lines in listy:
        # print(lines)
        a_list = list(lines.split())
        # print(a_list)
        short_list = []
        return_list = []
        for each in range(0, len(a_list)):
            # print(a_list[each])
            if a_list[each].isdigit() :
                each_int = int(a_list[each])
                # print(each_int)
                short_list.append(each_int)
            elif "." in a_list[each]:
                each_float = float(a_list[each])
                short_list.append(each_float)
            else:
                short_list.append(a_list[each])
            tuply = tuple(short_list)
        print(tuply)
            # return_list.append(tuply)

        # print(return_list)

    # print(return_list)

如果我调用函数使用

print(reader("sample.cs1301"))

我能够获取单个元组 我无法将单个元组组合到列表中。 下面是输入文件sample.cs1301的内容

1 assignment_1 85 100 0.25
2 test_1 90 100 0.25
3 exam_1 95 100 0.5

我可以得到如下的单个元组

(1, 'assignment_1', 85, 100, 0.25)
(2, 'test_1', 90, 100, 0.25)
(3, 'exam_1', 95, 100, 0.5)

我在循环中感到困惑。我尝试到处搜索，但不知何故它不适合我。

Answer 1

修复原代码

def reader(a_file):
    file = open(a_file, "r")
    listy = file.readlines()
    file.close()         # Always close if not using with
    # print(listy)
    # print(type(listy))
    return_list = []
    for lines in listy:
        # print(lines)
        a_list = list(lines.split())
        # print(a_list)
        short_list = []
        
        for each in range(0, len(a_list)):
            # print(a_list[each])
            if a_list[each].isdigit() :
                each_int = int(a_list[each])
                # print(each_int)
                short_list.append(each_int)
            elif "." in a_list[each]:
                each_float = float(a_list[each])
                short_list.append(each_float)
            else:
                short_list.append(a_list[each])
            tuply = tuple(short_list)
        print(tuply)
        return_list.append(tuply)   # Need to append tuple to results list
        
    print(return_list)

    return return_list              # Return the resulting list

reader('sample.cs1301')

改进建议

1. 使用 try/except 检查是否根据类型转换数字
2. 逐行遍历文件
3. 删除行尾的换行符
4. 文件后缀为 txt 以便 Window/Mac 系统知道文件的类型，即“sample.cs1301.txt”

改进的代码

def reader(filenm):
    with open(filenm, "r") as f:
        result = []
        for line in f:
            a_list = line.rstrip().split()  # rstrip to remove new line at end of line
            values = []
            for value in a_list:
                try:
                    values.append(int(value)) 
                except ValueError:                  
                    try:                         # Not int
                        values.append(float(value))
                    except ValueError:           # Not float                                              
                        values.append(value)   

            result.append(tuple(values))       # Appending values as tuple
            
    return result

print(reader('sample.cs1301.txt'))             # Use txt as file suffix

输出

[(1, 'assignment_1', 85, 100, 0.25),
 (2, 'test_1', 90, 100, 0.25),
 (3, 'exam_1', 95, 100, 0.5)]