length mismatch in folium?

Question

I'm working on coding a folium map and I keep getting this error. I'm new to this and honestly have no idea how to fix this.

import folium

geojson_map = 'https://raw.gituserhubcontent.com/dirkkoolmees/maps-import-export-of-fossil-fuels-/master/custom.geo.json'

world_map = folium.Map(location=[0,0], zoom_start = 1.5, tiles = 'CartoDB positron', min_zoom = 1, max_zoom = 6)

folium.Choropleth(
    geo_data = geojson_map,
    name = "chloropleth",
    data = df_clean,
    columns = [df.index, 'value'],
    key_on= 'feature.properties.name_sort',
    fill_color = 'Reds',
    fill_opacity = 0.9,
    line_opacity = 0.2,
    legend_name = 'GDP'
    ).add_to(world_map)

world_map

this is the error I receive:

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<ipython-input-31-b88f980d229d> in <module>()
     13     fill_color = 'Reds',
     14     fill_opacity = 0.9,
---> 15     line_opacity = 0.2,
     16     #legend_name = 'GDP'
     17     ).add_to(world_map)

1 frames
/usr/local/lib/python3.7/dist-packages/pandas/core/frame.py in set_index(self, keys, drop, append, inplace, verify_integrity)
   4597                 # ensure_index_from_sequences would not raise for append=False.
   4598                 raise ValueError(
-> 4599                     f"Length mismatch: Expected {len(self)} rows, "
   4600                     f"received array of length {len(arrays[-1])}"
   4601                 )

ValueError: Length mismatch: Expected 154 rows, received array of length 324

Does anybody know how to fix this? Thank you!

@MadPhysicist I'm not positive what exactly you mean by that. Could you show me how It would be properly formatted? Thanks — Chase Leibowitz, Dec 03 '21 at 18:19
Separate `folium.Choropleth(...).add_to(world_map)` into `c = folium.Choropleth(...); c.add_to(world_map)` — Mad Physicist, Dec 03 '21 at 18:38
It's not the same error because now it tells you which part actually causes the error — Mad Physicist, Dec 03 '21 at 19:53
first you could use `print()` to see what you have in variables - and what are sizes of data. ie `len(geojson_map)`, `len(df_clean)` - probably one of them has size 154 and other 324 and this can makes problem. OR maybe problem makes `df.index` ? — furas, Dec 03 '21 at 22:21
@furas It seems the geojson_map has a length of 105 while the data frame has a length of 154. Would I need to shorten my dataframe to work? — Chase Leibowitz, Dec 07 '21 at 15:39

score 0 · Answer 1 · answered Dec 28 '21 at 10:18

there are a few errors in your code
1. URL to GitHub is wrong
2. neither df_clean or df are defined
fixing these, the code works, noting there are 175 geometries in your GeoJSON
it's not clear what you are trying to achieve, but this code then works. Not sure why you are using df and df_clean that can have different numbers of rows

import folium
import numpy as np
import pandas as pd

geojson_map = 'https://raw.githubusercontent.com/dirkkoolmees/maps-import-export-of-fossil-fuels-/master/custom.geo.json'

world_map = folium.Map(location=[0,0], zoom_start = 1.5, tiles = 'CartoDB positron', min_zoom = 1, max_zoom = 6)

# code is using two different dataframes! create them...
df_clean = pd.DataFrame(index=range(175), data={"value":np.linspace(1,5,175)})
df = pd.DataFrame(index=range(175))

folium.Choropleth(
    geo_data = geojson_map,
    name = "chloropleth",
    data = df_clean,
    columns = [df.index, 'value'],
    key_on= 'feature.properties.name_sort',
    fill_color = 'Reds',
    fill_opacity = 0.9,
    line_opacity = 0.2,
    legend_name = 'GDP'
    ).add_to(world_map)

world_map

length mismatch in folium?

1 Answers1