CODEWITHSUNDEEP
pythonstringpandascsvdataframe
Marima
Marima

Reputation: 13

Converting CSV data to string

So I got a CSV file that has 14 columns, and I was trying to convert that data to string type and I tried this 

import pandas as pd
df = pd.read_csv("2008_data_test.csv", sep=",")
output = pd.DataFrame(columns=df.columns)
for c in df.columns:
    if df[c].dtype == object:
        print "convert ", df[c].name, " to string"
        df[c] = df[c].astype(str)
    output.to_csv("2008_data_test.csv_tostring2.csv", index=False)

This gives me the headers only, and I can't figure out what I missed?

Any ideas? And is it possible to convert specific columns?

Upvotes: 0

Views: 2752

Answers (1)

cs95
cs95

Reputation: 403208

You're modifying one dataframe, but writing another, that's the reason. Use select_dtypes instead.

c = df.select_dtypes(include=[object]).columns
df[c] = df[c].astype(str)

df.to_csv("2008_data_test.csv_tostring2.csv", index=False)

As MaxU suggested, it might be simpler to do filter by dtypes in this manner:

c = df.columns[df.dtypes.eq('object')]

The former creates a dataframe subslice before accessing columns, so this should be cheaper.

If you want to convert specific columns only, you can remove columns as needed from c before the conversion using c = c.difference(['Col1', 'Col2', ...]).

Upvotes: 1

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