How to create DataFrame in pandas python

Question

I have a csv file.

index  value    d F
0    975  25.35   5
1    976  26.28   4
2    977  26.24   1
3    978  25.76   0
4    979  26.08   0

I created a dataframe from CSV file this way. df = pd.read_csv("ThisFileL.csv")

I want to reconstruct a new DataFrame in my way by coppying the 2nd Columns three times.

data = pd.DataFrame()
data.add(df.value)
data.add(df.value)
data.add(df.value)

But it didn't work out. How can I do that?

CT Zhu · Accepted Answer · 2014-03-14 02:50:10Z

3

Have you tried data['value1']=data['value'], data['value2']=data['value'], etc? It should create new columns holding the numbers in value.

answered Mar 14, 2014 at 2:50

CT Zhu

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Comments

Nilani Algiriyage · Accepted Answer · 2014-03-14 06:30:25Z

2

You can do it by assigning 'value' column data in to new columns of the DataFrame.

df = pd.read_csv("ThisFileL.csv" , sep=' ')
df['value1'] = df.value
df['value2'] = df.value

The output of this would have following column headings.

index | value | d | F | value1 | value2

answered Mar 14, 2014 at 6:30

Nilani Algiriyage

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munk · Accepted Answer · 2014-03-14 03:58:42Z

1

Creating a new column in a DataFrame is pretty straightforward. df[column_label] = values

What you're going to have to do is come up with some good names for your columns. I'll use a, b and c in this example.

df = pd.read_csv("ThisFileL.csv")
new_df = pd.DataFrame()
for key in ('a', 'b', 'c'):
    new_df[key] = df['value']

answered Mar 14, 2014 at 3:58

munk

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