I'm trying to replace header string of my csv file with pandas libraries, but i can't understand how can I do this.
I try to see DataFrame but i don't see anything to do this.
anyone can help me?
thanks
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What do you mean by replace header? Do you mean skip when importing? or read, change then write back out?tmthydvnprt– tmthydvnprt2016-03-13 12:07:42 +00:00Commented Mar 13, 2016 at 12:07
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Ok i've found DataFrame.replace method and it works!tafazzi87– tafazzi872016-03-13 12:46:07 +00:00Commented Mar 13, 2016 at 12:46
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2 Answers
From a glance at the docs, it looks like it would be something like
df = pandas.Dataframe.read_csv(filename, ...)
new_header = ['new', 'column', 'names']
df.to_csv(new_filename, header=new_header, ...)
Comments
Reading csv files in Pandas
There are many options available when reading csv files. Here are some examples:
import pandas as pd
from cStringIO import StringIO
fake_csv_file = '''Col1,Col2,Col3
1,2,3
4,5,6
7,8,9'''
print 'Original CSV:'
print fake_csv_file
print
print 'Read in CSV File:'
df = pd.read_csv(StringIO(fake_csv_file))
print df
print
print 'Read in CSV File using multiple header lines:'
df = pd.read_csv(StringIO(fake_csv_file), header=[0,1])
print df
print
print 'Read in CSV File ignoring header rows:'
df = pd.read_csv(StringIO(fake_csv_file), skiprows=2)
print df
print
Original CSV:
Col1,Col2,Col3
1,2,3
4,5,6
7,8,9
Read in CSV File:
Col1 Col2 Col3
0 1 2 3
1 4 5 6
2 7 8 9
Read in CSV File using multiple header lines:
Col1 Col2 Col3
1 2 3
0 4 5 6
1 7 8 9
Read in CSV File ignoring header rows:
4 5 6
0 7 8 9
Writing csv files in Pandas
There are many options available when writing css files. Take careful note at the placement of commas in the final output in some the code below. Here are some examples:
# Set DataFrame back to original
df = pd.read_csv(StringIO(fake_csv_file))
print 'Write out a CSV file:'
print df.to_csv()
print
print 'Write out a CSV file with different headers:'
print df.to_csv(header=['COLA','COLB','COLC'])
print
print 'Write out a CSV without the pandas added index:'
print df.to_csv(index=False)
print
Write out a CSV file:
,Col1,Col2,Col3
0,1,2,3
1,4,5,6
2,7,8,9
Write out a CSV file with different headers:
,COLA,COLB,COLC
0,1,2,3
1,4,5,6
2,7,8,9
Write out a CSV without the pandas added index:
Col1,Col2,Col3
1,2,3
4,5,6
7,8,9
Notes:
StringIOand inline text is for example only. Normally, to read a specific file you'd usedf = pd.read_csv('/path/to/file.csv')to_csvwithout a file is used for example only. Normally, to write a specific file you'd usedf.to_csv('/path/to/file.csv')
