python - 错误处理但仍然收到 ValueError

Question

我正在努力解决这个关于错误处理的挑战。也许我离题太远了!

挑战说明:

Write a function called "load_file" that accepts one parameter: a filename. The function should open the file and return the contents.

If the contents of the file can be interpreted as an integer, return the contents as an integer. Otherwise, if the contents of the file can be interpreted as a float, return the contents as a float. Otherwise, return the contents of the file as a string.

You may assume that the file has only one line.

我收到 ValueError: could not convert string to float: "b>a!\{\'"

错误处理是我的错吗？

def load_file(file):
    
    file = open(file, "r")
    all_lines = file.read()
    
    try:        
        return int(all_lines)
    
    except ValueError:
        return float(all_lines)
            
    else:
        return all_lines
            
   
    file.close()

Answer 1

你需要做类似的事情

with open(file, "r") as file_handle:
    all_lines = file.read()
    try:
        return int(all_lines)
    except ValueError:
        pass
    try:
        return float(all_lines)
    except ValueError:
        pass

    return all_lines

重点是您根本不关心这些错误，因为它们只是意味着您需要继续进行下一个选项。

我还要指出 with 构造负责为您关闭文件。如果你想执行 file = open(file, "r") 那么你需要将你的返回值存储到一个变量中，然后执行 file.close()在你返回之前。