First of all I’m not an English-Speaker, I will do my best to explain my problem. Ask for clarification if necessary!
I’m trying to create a Dash app that must:
- Read a csv file and convert it to a dataframe
- Subset this dataframe according to the user’s choices
- Generate the subseted dataframe in a csv file
I got two dataframes gas3 and gas4 that I use in specific cases.
I want to generate a dataframe (gas_genere) based on gas3 or gas4 in function of the user’s choices. He can filter the dataframe by:
- Date (DatePickerRange)
- Flag (radio button)
- Inlet (checklist)
- Minimum and maximum temperature values (input)
All the variables containing this information are in gas3 and gas4. Here is a “test” code (Some packages might be useless here, don’t pay attention to them):
import dash
import dash_core_components as dcc # Graphs
import dash_html_components as html # Tags
from dash.dependencies import Input, Output, Event, State
import time
import pandas as pd
import plotly
import numpy as np
import statistics
from datetime import *
from pytz import *
import io
import urllib.parse
### Dataframe import
gas3 = pd.read_csv("C:/Path/gas3.csv", sep=';') # first data frame
gas4 = pd.read_csv("C:/Path/gas4.csv", sep=';') # second data frame
gas3['Date_Local_Time'] = pd.to_datetime(gas3['Date_Local_Time'], format='%Y/%m/%d %H:%M') # String to datetime
gas4['Date_Local_Time'] = pd.to_datetime(gas4['Date_Local_Time'], format='%Y/%m/%d %H:%M') # String to datetime
external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']
app = dash.Dash(__name__, external_stylesheets=external_stylesheets) # Starting application
app.layout = html.Div(children=[ # HTML of the entire project
### Date picker range
html.Div([
html.Label("Choose your time period :",
htmlFor='date_picker_range',
),
html.Br(),
html.Br(),
dcc.DatePickerRange(
id='date-picker-range',
min_date_allowed=gas3['Date_Local_Time'][0].date(),
max_date_allowed=gas3['Date_Local_Time'][len(gas3)-1].date(),
start_date=gas3['Date_Local_Time'][0].date(),
end_date=gas3['Date_Local_Time'][len(gas3)-1].date(),
start_date_placeholder_text='Start date',
end_date_placeholder_text='End date',
display_format = 'DD/MM/YYYY'
),
html.Br(),
html.Br()
]),
### Flag Choice
html.Div([
html.Label("Select a flag :",
htmlFor='radioflag',
),
html.Br(),
html.Br(),
dcc.RadioItems(
id='radioflag',
options=[
{'label': 'Flag 0', 'value': 'Flag0'},
{'label': 'Flag 1', 'value': 'Flag1'},
{'label': 'Flag 3', 'value': 'Flag3'},
{'label': 'Chambre à flux', 'value': 'CAF'}
]
),
html.Br(),
]),
### Inlet(s) choice
html.Div(children=[
html.Label("Select one or several inlet(s) :",
htmlFor='checkbox_1',
),
html.Br(),
html.Br(),
html.Div(style={'width':'15%', 'height':'100%','float':'left'},
children=[dcc.Checklist(id='ST1', className ='checkbox_1',
options=[
{'label': 'Inlet 1 ST1', 'value': 'I1ST1'},
{'label': 'Inlet 2 ST1', 'value': 'I2ST1'},
{'label': 'Inlet 3 ST1', 'value': 'I3ST1'},
{'label': 'Inlet 4 ST1', 'value': 'I4ST1'},
{'label': 'Inlet 5 ST1', 'value': 'I5ST1'},
{'label': 'Inlet 6 ST1', 'value': 'I6ST1'}
],
values=[],
labelStyle = {'display': 'block'}
)
]
),
]
),
html.Br(),
html.Br(),
html.Br(),
html.Br(),
### Minimum temperature :
html.Div(style={'width':'20%', 'height':'100%','float':'left'},
children=[
html.Label("Minimum temperature (°C) :",
htmlFor='tempmin',
),
html.Br(),
dcc.Input(
id = 'tempmin',
placeholder='Enter a value',
type='float',
value=''
)
]
),
### Maximum temperature :
html.Div([
html.Label("Maximum temperature (°C) :",
htmlFor='tempmax',
),
html.Br(),
dcc.Input(
id = 'tempmax',
placeholder='Enter a value',
type='float',
value=''
)
]
),
### Download button
html.Div(id='table'),
html.A(
'Download Data',
id='download-link',
download="gas_genere.csv",
href="",
target="_blank"
)
])
### Subset function
def filter_data(date1, date2, flag, ST1, tempmin, tempmax):
if flag == 'Flag0':
gas_genere = gas3[gas3['Flag']==0]
elif flag == 'Flag1':
gas_genere = gas4.copy()
elif flag == 'Flag3':
gas_genere = gas3[gas3['Flag']==3]
elif flag == 'CAF':
gas_genere = gas3[gas3['3PV4']==1]
else:
gas_genere = gas3.copy()
# gas_genere = gas_genere[(gas_genere['Temperature_air']>= tempmin) & (gas_genere['Temperature_air']<= tempmax)]
# gas_genere = gas_genere[gas_genere['ST_Valve'] in ST1]
# gas_genere = gas_genere[(gas_genere['Date_Local_Time'].time()>= date1) & (gas_genere['Date_Local_Time'].time()<= date2)]
return gas_genere
### Callback :
@app.callback(
Output('download-link', 'href'),
[Input('date-picker-range', 'start_date'),
Input('date-picker-range', 'end_date'),
Input('radioflag', 'value'),
Input('ST1', 'values'),
Input('tempmin', 'value'),
Input('tempmax', 'value')])
### Update download link
def update_download_link(date1, date2, flag, ST1, tempmin, tempmax):
gas_genere = filter_data(date1, date2, flag, ST1, tempmin, tempmax)
csv_string = gas_genere.to_csv(index=False, encoding='utf-8', sep=';')
csv_string = "data:text/csv;charset=utf-8,%EF%BB%BF" + urllib.parse.quote(csv_string)
return csv_string
if __name__ == '__main__':
app.run_server(debug=True)
To subset my dataframe, I use the filter_data function. But it does not work very well! I put all the “filtering lines” that does not work in comments #.
Actually, the only thing that works is my radiobutton to choose a “Flag”. I can easily generate a csv file by choosing the “Flag” I want:
But I can’t choose a date range, a mininum/maximum temperature or one/several inlets. If I remove the # corresponding to one of these lines, I got this kind of csv file:
What’s wrong with my code?
Thank you!