是否可以在 Dash 中上传 csv 文件并将其存储为 pandas DataFrame?
Is it possible to upload a csv file in Dash and also store it as a pandas DataFrame?
我正在使用 Python 在 Dash 中开发一个仪表板,在其中一个核心组件中,我试图上传一个 csv 文件并以数据 table 格式显示它(见下文)。效果很好(见图),我遵循了这个例子:https://dash.plotly.com/dash-core-components/upload
但是,我还想在代码后面使用 table 作为 pandas DataFrame。由于我在 运行 仪表板代码后上传了 csv 文件,因此我找不到将 csv 内容 return 作为 DataFrame 的方法。有什么方法可以做到这一点?我的代码如下。
Dash app output
提前致谢!
###############################################################################
# Upload files
# https://dash.plotly.com/dash-core-components/upload
###############################################################################
def parse_contents(contents, filename, date):
content_type, content_string = contents.split(',')
decoded = base64.b64decode(content_string)
try:
if 'csv' in filename:
# Assume that the user uploaded a CSV 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))
except Exception as e:
print(e)
return html.Div([
'There was an error processing this file.'
])
trade_upload = pd.DataFrame(df)
return dbc.Table.from_dataframe(trade_upload)
@app.callback(Output('output-data-upload', 'children'),
[Input('upload-data', 'contents')],
[State('upload-data', 'filename'),
State('upload-data', 'last_modified')])
def update_output(list_of_contents, list_of_names, list_of_dates):
if list_of_contents is not None:
children = [
parse_contents(c, n, d) for c, n, d in
zip(list_of_contents, list_of_names, list_of_dates)]
return children
if __name__ == '__main__':
app.run_server(port=8051, debug=False)
定义parse_contents
函数时,只需return df
:
def parse_contents(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 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))
except Exception as e:
print(e)
return html.Div([
'There was an error processing this file.'
])
return df
然后,您可以在以下回调中调用 parse_contents
并生成 pandas 数据帧:
@app.callback(
Output('table-container', 'data'),
[Input('file_upload', 'contents')],
State('file_upload', 'filename'))
def filter_df(content, name):
if content is not None:
# Return all the rows on initial load/no country selected.
df = parse_contents(content, name)
dff = df.to_json()
dff_pandas = pd.Dataframe(dff)
else:
df = parse_contents(content, name)
dff = df.to_json()
dff_pandas = pd.Dataframe(dff)
dff_pandas_filtered = dff_pandas.query('column_A == 012345')
您可以将其保留为全局变量。这是单个文件上传的代码。
1.Layout
dcc.Upload(
id='upload-data',
children=html.Div([
'Drag and Drop or ',
html.A('Select Files')
]),
style={
'width': '100%',
'height': '60px',
'lineHeight': '60px',
'borderWidth': '1px',
'borderStyle': 'dashed',
'borderRadius': '5px',
'textAlign': 'center',
'margin': '10px'
},
# Allow multiple files to be uploaded
multiple=False
),
html.Div(id='output-data-upload'),
])
2.Function
def parse_contents(contents, filename, date):
content_type, content_string = contents.split(',')
global df#define data frame as global
decoded = base64.b64decode(content_string)
try:
if 'csv' in filename:
# Assume that the user uploaded a CSV 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))
except Exception as e:
print(e)
return html.Div([
'There was an error processing this file.'
])
return html.Div([
html.H5(filename),
html.H6(datetime.datetime.fromtimestamp(date)),
dash_table.DataTable(
data=df.to_dict('records'),
columns=[{'name': i, 'id': i} for i in df.columns]
),
html.Hr(), # horizontal line
# For debugging, display the raw contents provided by the web browser
html.Div('Raw Content'),
html.Pre(contents[0:200] + '...', style={
'whiteSpace': 'pre-wrap',
'wordBreak': 'break-all'
})
])
3.Callback
@app.callback(Output('output-data-upload', 'children'),
Input('upload-data', 'contents'),
State('upload-data', 'filename'),
State('upload-data', 'last_modified'))
def update_output(content, filename, date):
children=parse_contents(content, filename, date)
print(type(df))#this will show data type as a pandas dataframe
print(df)
return children
我正在使用 Python 在 Dash 中开发一个仪表板,在其中一个核心组件中,我试图上传一个 csv 文件并以数据 table 格式显示它(见下文)。效果很好(见图),我遵循了这个例子:https://dash.plotly.com/dash-core-components/upload
但是,我还想在代码后面使用 table 作为 pandas DataFrame。由于我在 运行 仪表板代码后上传了 csv 文件,因此我找不到将 csv 内容 return 作为 DataFrame 的方法。有什么方法可以做到这一点?我的代码如下。
Dash app output
提前致谢!
###############################################################################
# Upload files
# https://dash.plotly.com/dash-core-components/upload
###############################################################################
def parse_contents(contents, filename, date):
content_type, content_string = contents.split(',')
decoded = base64.b64decode(content_string)
try:
if 'csv' in filename:
# Assume that the user uploaded a CSV 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))
except Exception as e:
print(e)
return html.Div([
'There was an error processing this file.'
])
trade_upload = pd.DataFrame(df)
return dbc.Table.from_dataframe(trade_upload)
@app.callback(Output('output-data-upload', 'children'),
[Input('upload-data', 'contents')],
[State('upload-data', 'filename'),
State('upload-data', 'last_modified')])
def update_output(list_of_contents, list_of_names, list_of_dates):
if list_of_contents is not None:
children = [
parse_contents(c, n, d) for c, n, d in
zip(list_of_contents, list_of_names, list_of_dates)]
return children
if __name__ == '__main__':
app.run_server(port=8051, debug=False)
定义parse_contents
函数时,只需return df
:
def parse_contents(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 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))
except Exception as e:
print(e)
return html.Div([
'There was an error processing this file.'
])
return df
然后,您可以在以下回调中调用 parse_contents
并生成 pandas 数据帧:
@app.callback(
Output('table-container', 'data'),
[Input('file_upload', 'contents')],
State('file_upload', 'filename'))
def filter_df(content, name):
if content is not None:
# Return all the rows on initial load/no country selected.
df = parse_contents(content, name)
dff = df.to_json()
dff_pandas = pd.Dataframe(dff)
else:
df = parse_contents(content, name)
dff = df.to_json()
dff_pandas = pd.Dataframe(dff)
dff_pandas_filtered = dff_pandas.query('column_A == 012345')
您可以将其保留为全局变量。这是单个文件上传的代码。
1.Layout
dcc.Upload(
id='upload-data',
children=html.Div([
'Drag and Drop or ',
html.A('Select Files')
]),
style={
'width': '100%',
'height': '60px',
'lineHeight': '60px',
'borderWidth': '1px',
'borderStyle': 'dashed',
'borderRadius': '5px',
'textAlign': 'center',
'margin': '10px'
},
# Allow multiple files to be uploaded
multiple=False
),
html.Div(id='output-data-upload'),
])
2.Function
def parse_contents(contents, filename, date):
content_type, content_string = contents.split(',')
global df#define data frame as global
decoded = base64.b64decode(content_string)
try:
if 'csv' in filename:
# Assume that the user uploaded a CSV 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))
except Exception as e:
print(e)
return html.Div([
'There was an error processing this file.'
])
return html.Div([
html.H5(filename),
html.H6(datetime.datetime.fromtimestamp(date)),
dash_table.DataTable(
data=df.to_dict('records'),
columns=[{'name': i, 'id': i} for i in df.columns]
),
html.Hr(), # horizontal line
# For debugging, display the raw contents provided by the web browser
html.Div('Raw Content'),
html.Pre(contents[0:200] + '...', style={
'whiteSpace': 'pre-wrap',
'wordBreak': 'break-all'
})
])
3.Callback
@app.callback(Output('output-data-upload', 'children'),
Input('upload-data', 'contents'),
State('upload-data', 'filename'),
State('upload-data', 'last_modified'))
def update_output(content, filename, date):
children=parse_contents(content, filename, date)
print(type(df))#this will show data type as a pandas dataframe
print(df)
return children