CODEWITHSUNDEEP
python-3.xpandasdataframe
RichardWiggles
RichardWiggles

Reputation: 5

Appending a list to a dataframe in Python

I'm trying to add a list as the 3rd column in a dataframe in a simple program, but keep getting the error

RuntimeWarning: '<' not supported between instances of 'str' and 'int', sort order is undefined for incomparable objects result = result.union(other)

Basically the program should look through the data and find matches of names, then add those along with their time value to a new data set. But I can't get anything to add onto the dataframe after the if statement. The dataframe already has 2 columns that use strings (the 'Name' and 'Time' column) and nothing uses ints so it doesn't make sense why this error comes up. The only thing I've been successful in getting to append is the "matches" which is already in the dataframe. But that is a list just like "test1".

Thank you in advance for any help you can give.

import os
import csv
import fileinput
import codecs
import pandas as pd
import os
os.chdir('/home/richardwiggles/Desktop')

df1 = pd.read_csv('df1.csv', names=['Place','Name','Time','City','State','Age'])
df2 = pd.read_csv('df2.csv', names=['Name','Time'])
test1 = ['a','b','c']

matchesDF = pd.DataFrame()
matches = []

for finishers in df1['Name']:
    matches.append(df2[df2['Name'].str.match(finishers)])

matchesDF=matchesDF.append(matches, ignore_index=True)
matchesDF=matchesDF.append(test1, ignore_index=True)
matchesDF.to_csv(r'/home/richardwiggles/Desktop/data1.csv')

The df1 in excel looks like this:

Place Name City State Time
1 name1 city1 state1 2:39:06
2 name2 city2 state2 2:39:46
3 name3 city3 state3 2:40:25
4 name4 city4 state4 2:41:44
5 name5 city5 state5 2:45:07

df2 in excel looks like this

Name Finish
name1 2:31:20
name2 2:33:14
name3 2:34:44
name4 2:35:39
name5 2:36:00

Upvotes: 0

Views: 154

Answers (1)

Simanti
Simanti

Reputation: 26

I created dummy dataframes and worked with your code, its working for me, with different names etc. Without knowing your dataframe, exact issue can not be deciphered. However, try using astype(str) before .str.match .

import os
import csv
import fileinput
import codecs
import pandas as pd
import os

data = {'Place':['EU', 'can', 'in', 'brz'],
        'Name':['alex', 'tom', 'ken', 'keth'],
        'Time': ['20:30','10:45','5:15','2:10'],
        'City' : ['alt','rtx','fgd','hgf'],
        'State' : ['az', 'kz','bz', 'cz'],
        'Age' : [20,30,40,50]}

data2 = {'Name' : ['alex','keth',' '],
         'Time' : ['10:10','7:05','5:15']}

df1 = pd.DataFrame(data)
df2 = pd.DataFrame(data2)

test1 = ['a','b','c']

matchesDF = pd.DataFrame()
matches = []

for finishers in df1['Name']:
    matches.append(df2[df2['Name'].astype(str).str.match(finishers)])

matchesDF=matchesDF.append(matches, ignore_index=True)
matchesDF=matchesDF.append(test1, ignore_index=True)


matchesDF

output:
    Name    Time    0
    0   alex    10:10   NaN
    1   keth    7:05    NaN
    2   NaN NaN a
    3   NaN NaN b
    4   NaN NaN c

br, Simanti.

Upvotes: 0

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