AttributeError

Question

我正在尝试运行此代码：

def parse_data(contents, filename):
    content_type, content_string = contents.split(',')

    decoded = base64.b64decode(content_string)
    try:
        if 'csv' in filename:
            # Assume that the user uploaded a CSV or TXT file
            df = pd.read_csv(
                io.StringIO(decoded.decode('utf-8')))
        elif 'xls' in filename:
            # Assume that the user uploaded an excel file
            df = pd.read_excel(io.BytesIO(decoded))
        elif 'txt' or 'tsv' in filename:
            # Assume that the user upl, delimiter = r'\s+'oaded an excel file
            df = pd.read_csv(
                io.StringIO(decoded.decode('utf-8')), delimiter = r'\s+')
    except Exception as e:
        print(e)
        return html.Div([
            'There was an error processing this file.'
        ])

    return df

def update_graph(contents, filename):
    fig = {
        'layout': go.Layout(
            plot_bgcolor=colors["graphBackground"],
            paper_bgcolor=colors["graphBackground"])
    }

    if contents:
        contents = contents[0]
        filename = filename[0]
        df = parse_data(contents, filename)
        df = df.set_index(df.columns[0])
        fig['data'] = df.iplot(asFigure=True, kind='scatter', mode='lines+markers', size=1)


    return fig

并得到这个错误：

Traceback (most recent call last):
  File "/Users/.../PycharmProjects/pythonProject2/main.py", line 93, in update_graph
    df = df.set_index(df.columns[0])
AttributeError: 'Div' object has no attribute 'set_index'

任何想法可能是错误的？非常感谢！

Answer 1

所有问题都出在您的 parse_data() 上。如果它不能读取文件然后它运行 return html.Div() 所以运行 df = parse_data() 意味着 df = html.Div() 然后你不检查你是否真的在 df 中获取数据df.set_index() 表示 html.Div().set_index().

也许最好使用 return None 并在 df = parse_data()

之后检查

def parse_data(contents, filename):
    # ... code ...

    try:

       # ... code ...

    except Exception as e:
        print(e)
        return None

    return df

以后

    df = parse_data(contents, filename)

    if df is None:
        html.Div(['There was an error processing this file.'])
    else:
        df = df.set_index(df.columns[0])
        fig['data'] = df.iplot(asFigure=True, kind='scatter', mode='lines+markers', size=1)

但是当 fig['data'] 无法读取文件时，这仍然会有问题。

我无法测试你的代码，但也许它应该将 Div 分配给 fig['data']

if df is None:
    fig['data'] = html.Div(['There was an error processing this file.'])
else:
    df = df.set_index(df.columns[0])
    fig['data'] = df.iplot(asFigure=True, kind='scatter', mode='lines+markers', size=1)

AttributeError - 'Div' 对象没有属性 'set_index'

AttributeError - 'Div' object has no attribute 'set_index'

python

callback

plotly-dash