CODEWITHSUNDEEP
pythonlistdataframeappend
Kratos
Kratos

Reputation: 1114

create panda dataframe and append values in for loop

I have a list from which I would like to iterate over and create tuples in a pandas dataframe in order to imitate sliding window of size 4. What I am trying to do is:

tuples = pd.DataFrame()
for index, row in expertsDF.iterrows():
      newlst = row['name'] 
      counter = 0
      for x in newlst:
        if counter < len(newlst) - 3:
            tuples['A'] = x
            tuples['B'] =newlst(counter+1)
            tuples['C'] =newlst(counter+2)
            tuples['D'] =newlst(counter+3)
            counter = counter + 1

the newlst looks like this:

list (var1, var2, var3....)

and my DataFrame should be like this:

     A       B      C       D
1   var1   var2   var3    var4
2   var2   var3   var4    var5
3   var3   var4   var5    var6

Is there a way to do that in python?

Upvotes: 1

Views: 549

Answers (2)

akovner
akovner

Reputation: 118

How about creating the DataFrame from Series objects?

import pandas as pd

data_list = list(map(lambda x: 'var{}'.format(x),range(0,100)))
df = pd.Series(data_list[0:97]).to_frame(name='A')
df['B'] = pd.Series(data_list[1:98])
df['C'] = pd.Series(data_list[2:99])
df['D'] = pd.Series(data_list[3:100])

df.head()

# output
#       A     B     C     D
# 0  var0  var1  var2  var3
# 1  var1  var2  var3  var4
# 2  var2  var3  var4  var5
# 3  var3  var4  var5  var6
# 4  var4  var5  var6  var7

Upvotes: 1

nullop
nullop

Reputation: 554

Is this close?

import pandas as pd
tuples = pd.DataFrame(columns=['A', 'B', 'C', 'D'])
newlst = "abcdefg"
i = 0
for x in newlst:
    if i < len(newlst) - 3:
        t = pd.DataFrame([[x, newlst[i + 1], newlst[i + 2], newlst[i + 3]]],
                         columns=['A', 'B', 'C', 'D'])
    tuples = tuples.append(t, ignore_index=True)
    i += 1
print tuples

This prints:

   A  B  C  D
0  a  b  c  d
1  b  c  d  e
2  c  d  e  f
3  d  e  f  g

Upvotes: 1

Related Questions