Reproducible example:

import pandas as pd

tmp_scen = {'name': 'Current conditions',
 'actionSet': ['not_irrigated', 'cover_crop_none', 'mar_none'],
 'cost': 0.0,
 'totalNitrogen': 9.649798364504209,
 'totalPhosphorus': 2.4570326616674745,
 'sediment': 1.2039077716577735,
 'appliedWater': 11.607623110151138,
 'infiltrationVolume': 0.7424774065057028,
 'acres': 3.382359912104316,
 'irrType': 'not_irrigated'}

good_result = pd.DataFrame.from_dict(tmp_scen, orient = 'index')

tmp_scen = {'actionSet': ['not_irrigated', 'cover_crop_none', 'mar_none'],
 'name': 'Current conditions',
 'cost': 0.0,
 'totalNitrogen': 9.649798364504209,
 'totalPhosphorus': 2.4570326616674745,
 'sediment': 1.2039077716577735,
 'appliedWater': 11.607623110151138,
 'infiltrationVolume': 0.7424774065057028,
 'acres': 3.382359912104316,
 'irrType': 'not_irrigated'}

error_result = pd.DataFrame.from_dict(tmp_scen, orient = 'index')

Problem description

Error when creating a dataframe from a dictionary when the first item in the dictionary is a list. See reproducible example above. 

TypeError: object of type 'float' has no len()

Expected Output

Out[369]: 
                                                             0
actionSet           [not_irrigated, cover_crop_none, mar_none]
name                                        Current conditions
cost                                                         0
totalNitrogen                                           9.6498
totalPhosphorus                                        2.45703
sediment                                               1.20391
appliedWater                                           11.6076
infiltrationVolume                                    0.742477
acres                                                  3.38236
irrType                                          not_irrigated

Output of pd.show_versions()

INSTALLED VERSIONS ------------------ commit: None python: 3.7.3.final.0 python-bits: 64 OS: Windows OS-release: 10 machine: AMD64 processor: Intel64 Family 6 Model 158 Stepping 9, GenuineIntel byteorder: little LC_ALL: None LANG: en LOCALE: None.None pandas: 0.24.2 pytest: 4.4.1 pip: 19.0.3 setuptools: 40.8.0 Cython: 0.29.6 numpy: 1.16.2 scipy: 1.2.1 pyarrow: None xarray: None IPython: 7.4.0 sphinx: 1.8.5 patsy: 0.5.1 dateutil: 2.8.0 pytz: 2018.9 blosc: None bottleneck: 1.2.1 tables: 3.5.1 numexpr: 2.6.9 feather: None matplotlib: 3.0.3 openpyxl: 2.6.1 xlrd: 1.2.0 xlwt: 1.3.0 xlsxwriter: 1.1.5 lxml.etree: 4.3.2 bs4: 4.7.1 html5lib: 1.0.1 sqlalchemy: 1.3.1 pymysql: 0.9.3 psycopg2: None jinja2: 2.10 s3fs: None fastparquet: None pandas_gbq: None pandas_datareader: None gcsfs: None

Comment From: WillAyd

~~This seems to work fine on master, though not with the result you would expect~~. It is ambiguous as to whether you mean to get a 1 column data frame or a 3 column data frame and just made a programming mistake with this kind of construction.

Not sure if there is anything to do here. Note you can construct a Series instead if you want 1D

Comment From: asishm

@WillAyd both examples use the same dictionary albeit with a different order of keys.

Edit: a simpler example:

In [25]: pd.DataFrame.from_dict({'a': [1,2,3], 'b': 1}, orient='index')
# TypeError: object of type 'int' has no len()
In [26]: pd.DataFrame.from_dict({'b': 1, 'a': [1,2,3]}, orient='index')
Out[26]:
           0
b          1
a  [1, 2, 3]

Note that the initial object itself is the same in both examples. Python dicts aren't guaranteed insertion order until 3.7 (iirc).

Comment From: matttan90

Hey! I'm having a go at this.

Comment From: Dr4cky

Wow, I did not think changing the order would fix my issue, but it did. Having a list as the very first value in a dictionary gave me the 'object of type 'float' has no len()' error.