CODEWITHSUNDEEP
pythonpandasvalueerror
machinelearner07
machinelearner07

Reputation: 113

Fill with Nan when Length of values does not match length of index

I want a dataframe that looks like this. 

 a         b
cars      New
bikes     nan
trains    nan

Assume the following...

list(oldDF["Transportation"].unique())=["cars", "bikes", "trains"]
list(oldDF["Condition"].unique())=["New"]

My Code Looks like this Currently:

newList=["Transportation", "Condition"]
newDF=pf.DataFrame(columns=newList)

for i in newList:
    newDF[i]= list(oldDF[i].unique())

I want to be able to print the dataframe above and fill missing values with nan rather than getting a value error.

Upvotes: 2

Views: 1292

Answers (3)

BENY
BENY

Reputation: 323326

This is more like a hidden pivot problem 

oldDF.melt().drop_duplicates().\
      assign(index=lambda x : x.groupby('variable').cumcount()).\
            pivot('index','variable','value')
Out[62]: 
variable Condition Transportation
index                            
0              New           cars
1              NaN          bikes
2              NaN         trains

Upvotes: 2

piRSquared
piRSquared

Reputation: 294488

from_dict and orient='index'

pd.DataFrame.from_dict({n: c.unique() for n, c in oldDF.iteritems()}, orient='index').T

  Transportation Condition
0           cars       New
1          bikes      None
2         trains      None

zip_longest

from itertools import zip_longest

pd.DataFrame([*zip_longest(*map(pd.unique, map(oldDF.get, oldDF)))], columns=[*oldDF])

  Transportation Condition
0           cars       New
1          bikes      None
2         trains      None

Upvotes: 4

alex067
alex067

Reputation: 3301

use the fillna method to fill missing values with your choosing. 

df['Condition'] = df['Condition'].fillna('')

Upvotes: 1

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