我正在尝试遵循此交互式窗口小部件教程：
Python-Data Projects — Data Analysis UI Reinforced by Ipywidgets，
但是每次我遇到No CSV loaded错误时。当我尝试上传csv并单击Preview时，会发生这种情况。
import pandas as pd
import sys
from io import StringIO
import numpy as np
import matplotlib.pyplot as plt
import ipywidgets as widgets
%matplotlib inline
tab = widgets.Tab()
out = widgets.Output(layout={'border': '1px solid black'})
up = widgets.FileUpload(accept="", multiple=False)
delim = widgets.RadioButtons(
options=[';', ',', ' '],
description='Separator: ',
disabled=False)
eraser = widgets.SelectMultiple(
options=['tab','"'],
value=['tab'],
#rows=10,
description='Eraser: ',
disabled=False)
rows = widgets.IntSlider(
value=0,
step=1,
description='# of lines:',
disabled=False,
continuous_update=False,
orientation='horizontal',
readout=True,
readout_format='d')
button_upload = widgets.Button(
description='Upload',
disabled=False,
button_style='warning',
tooltip='Click to Upload',
icon='check')
button_preview = widgets.Button(
description='Preview',
disabled=False,
button_style='info',
tooltip='Click to Preview',
icon='search')
button_plot = widgets.Button(
description='Plot',
disabled=False,
button_style='danger',
tooltip='Click to Plot',
icon='pencil')
graph_type = widgets.Dropdown(
options=['Bar Chart', 'Line Chart'],
value='Bar Chart',
description='Chart Type:',
disabled=False)
x_axis = widgets.Dropdown(
options=[''],
value='',
description='X-Axis:',
disabled=False)
y_axis = widgets.Dropdown(
options=[''],
value='',
description='Y-Axis:',
disabled=False)
color_picker = widgets.ColorPicker(
concise=False,
description='Color Picker: ',
value='lightblue',
disabled=False)
toggle = widgets.ToggleButtons(
options=['Preview ', 'Info ', 'Stats '],
description='Options',
disabled=False,
button_style='warning',
icons=['search', 'info', 'tachometer'])
accordion = widgets.Accordion(children=[
up,
widgets.VBox([delim, eraser]),
rows])
accordion.set_title(0, 'File Selection')
accordion.set_title(1, 'Delimiter')
accordion.set_title(2, 'Skip Rows')
accordion_box = widgets.VBox([
accordion,
widgets.HBox([button_preview, button_upload]),
out
])
children = [
accordion_box,
widgets.VBox([toggle, out]),
widgets.VBox([
widgets.HBox([graph_type, color_picker]),
widgets.HBox([x_axis, y_axis]),
button_plot,
out
])]
tab.children = children
tab.set_title(0, "Upload")
tab.set_title(1, "Describer")
tab.set_title(2, "Plotter")
display(tab)
def content_parser():
if up.value == {}:
with out:
print('No CSV loaded')
else:
typ, content = "", ""
up_value = up.value
for i in up_value.keys():
typ = up_value[i]["metadata"]["type"]
if typ == "text/csv":
content = up_value[i]["content"]
content_str = str(content, 'utf-8')
if eraser.value != {}:
for val in eraser.value:
if val == "tab":
content_str = content_str.replace("\t","")
else:
content_str = content_str.replace(val,"")
if content_str != "":
str_io = StringIO(content_str)
return str_io
def df_converter():
content = content_parser()
if content is not None:
df = pd.read_csv(content, sep=delim.value, index_col=False, skiprows=rows.value)
return df
else:
return None
def preview():
df = df_converter()
with out:
out.clear_output()
print('\n -----Now this is how your DF looks like:----- \n')
if df is not None:
print(df.head(10))
else:
print('Configuration is wrong/missing...')
def upload():
df = df_converter()
with out:
out.clear_output()
print('\n --------Your uploaded DF looks like:-------- \n')
if df is not None:
print(df)
x_axis.options = df.columns
y_axis.options = df.columns
else:
print('Configuration is wrong/missing...')
def desc():
info_level = toggle.value
if info_level != {}:
df = df_converter()
with out:
out.clear_output()
print('\n ------Your {} looks like:------ \n'.format(
info_level))
if df is not None:
if info_level == 'Info ':
print(df.info(verbose=True))
elif info_level == 'Stats ':
print(df.describe())
elif info_level == 'Preview ':
print(df.head(5))
else:
print('Configuration is wrong/missing...')
def plot():
graph = graph_type.value
if graph != {}:
df = df_converter()
with out:
out.clear_output()
print('\n ------Your {} looks like:------ \n'.format(
graph))
if (df is not None):
df = df.head(5)
height = df[y_axis.value]
bars = df[x_axis.value]
y_pos = np.arange(len(height))
plt.figure(figsize=(10,4))
if graph == 'Bar Chart':
plt.bar(
y_pos,
height,
color=color_picker.value)
plt.xticks(y_pos, bars)
elif graph == 'Line Chart':
plt.plot(
bars,
height,
color=color_picker.value,
marker='o',
linestyle='solid'
)
plt.xticks(bars)
plt.show()
def preview_clicked(b):
preview()
def upload_clicked(b):
upload()
def desc_clicked(b):
desc()
def plotter_clicked(b):
plot()
button_preview.on_click(preview_clicked)
button_upload.on_click(upload_clicked)
toggle.observe(desc_clicked, 'value')
button_plot.on_click(plotter_clicked)