熊猫读csv正在改变列

Question

I'm trying to create a dataframe of a csv file that has 4 empty columns. When I open it on LibreOffice or Excel it correctly identifies the empty columns. However, opening with pd.read_csv() ends up shifting the columns' values by one.

How can I solve this? It seems like a problem with pandas read_csv() method.

My code is really standard:

import pandas as pd
df = pd.DataFrame.read_csv('csv_file.csv', sep=',')
df.head()

I changed the headers and used this:

df = pd.DataFrame.read_csv('csv_file.csv', sep=',', index_col=False).

This solved the problem, but what in my previous headers was causing this?

Answer 1

It seems you need the parameter index_col=False to NOT read the first column to index in read_csv , sep=',' parameter can be omitted, because it is the default value:

df = pd.read_csv('csv_file.csv', index_col=False)

Your sample:

df = pd.read_csv('teste2.csv', index_col=False)
print (df)
  Header1 Header2  Header3  Unnamed: 3  Unnamed: 4  Header4  Header5  Header6  \
0     ptn  M00001        0         NaN         NaN        2        0        0   

   Header7  Header8    ...     Header22  Header23  Header24  Header25  \
0        0  -31.573    ...       -0.375       0.0   -64.168   276.586   

   Header26  Header27  Unnamed: 29  Unnamed: 30  Header28  Header29  
0    -0.232       0.0          NaN          NaN     0.702       1.0  

[1 rows x 33 columns]

Answer 2

I encountered the same problem. Try writing headings on top of each column if there are none. This time, read_csv() also reads the headings and lists them.
After that convert the data frame to an array by

df=df.values 

and the headings are gone.

Answer 3

The problems occurs if your line ends with an delimiter (here comma[,]), which creates an empty cell generally not visible in MS Excel. If your csv line looks like this:

1,2282816,102.97245065789474,2432,0.8333333333333334,0.1388888888888889,certain,

then modify it to:

1,2282816,102.97245065789474,2432,0.8333333333333334,0.1388888888888889,certain

and pd.read_csv(fileName) will work fine.

Answer 4

I had a similar problem. Here is how I have solved it:

1. Opened excel file with google spreadsheet on google drive
2. Downloaded spread sheet as csv file
3. Read the csv file via pandas.read_csv('filename', sep=',', index_col=False))

Problem resolved.