CODEWITHSUNDEEP
pythonpython-3.xcsvpandas
RenamedUser7008
RenamedUser7008

Reputation: 57

reading a text file in python with variable spacing

I have the following data in the form of a text file which I would like to load into python:

      pclass  survived                                               name  
0          1         1                      Allen, Miss. Elisabeth Walton   
1          1         1                     Allison, Master. Hudson Trevor   
2          1         0                       Allison, Miss. Helen Loraine   
3          1         0               Allison, Mr. Hudson Joshua Creighton   
4          1         0    Allison, Mrs. Hudson J C (Bessie Waldo Daniels)   
5          1         1                                Anderson, Mr. Harry   
6          1         1                  Andrews, Miss. Kornelia Theodosia   
7          1         0                             Andrews, Mr. Thomas Jr   
8          1         1      Appleton, Mrs. Edward Dale (Charlotte Lamson)   
9          1         0                            Artagaveytia, Mr. Ramon   
10         1         0                             Astor, Col. John Jacob

Since the white space is not a constant and also since the last field(name) has a white space between them, I am having trouble parsing it. I tried the following: 

pd.read_csv("test.csv",sep = "\s+", header=0, index_col=0)

But it gives an error:

CParserError: Error tokenizing data. C error: Expected 7 fields in line 5, saw 8

Upvotes: 3

Views: 785

Answers (2)

Stephen Rauch
Stephen Rauch

Reputation: 49812

You can use pandas.read_fwf (aka: fixed width format) to do this:

Code:

df = pd.read_fwf(StringIO(data), header=1, index_col=0)

Test code:

from io import StringIO
import pandas as pd

data = u"""
      pclass  survived                                               name
0          1         1                      Allen, Miss. Elisabeth Walton
1          1         1                     Allison, Master. Hudson Trevor
2          1         0                       Allison, Miss. Helen Loraine
3          1         0               Allison, Mr. Hudson Joshua Creighton
4          1         0    Allison, Mrs. Hudson J C (Bessie Waldo Daniels)
5          1         1                                Anderson, Mr. Harry
6          1         1                  Andrews, Miss. Kornelia Theodosia
7          1         0                             Andrews, Mr. Thomas Jr
8          1         1      Appleton, Mrs. Edward Dale (Charlotte Lamson)
9          1         0                            Artagaveytia, Mr. Ramon
10         1         0                             Astor, Col. John Jacob"""

df = pd.read_fwf(StringIO(data), header=1, index_col=0)
print(df)

Results:

    pclass  survived                                             name
0        1         1                    Allen, Miss. Elisabeth Walton
1        1         1                   Allison, Master. Hudson Trevor
2        1         0                     Allison, Miss. Helen Loraine
3        1         0             Allison, Mr. Hudson Joshua Creighton
4        1         0  Allison, Mrs. Hudson J C (Bessie Waldo Daniels)
5        1         1                              Anderson, Mr. Harry
6        1         1                Andrews, Miss. Kornelia Theodosia
7        1         0                           Andrews, Mr. Thomas Jr
8        1         1    Appleton, Mrs. Edward Dale (Charlotte Lamson)
9        1         0                          Artagaveytia, Mr. Ramon
10       1         0                           Astor, Col. John Jacob

Upvotes: 2

piRSquared
piRSquared

Reputation: 294498

'\s+' assumes one or more spaces which still parses your final column. Instead use a regex that assumes two or more.

pd.read_csv("test.csv", sep="\s{2,}", header=0, index_col=0, engine='python')

Entire Working Example 

from io import StringIO
import pandas as pd

txt = """     pclass  survived                                               name  
0          1         1                      Allen, Miss. Elisabeth Walton   
1          1         1                     Allison, Master. Hudson Trevor   
2          1         0                       Allison, Miss. Helen Loraine   
3          1         0               Allison, Mr. Hudson Joshua Creighton   
4          1         0    Allison, Mrs. Hudson J C (Bessie Waldo Daniels)   
5          1         1                                Anderson, Mr. Harry   
6          1         1                  Andrews, Miss. Kornelia Theodosia   
7          1         0                             Andrews, Mr. Thomas Jr   
8          1         1      Appleton, Mrs. Edward Dale (Charlotte Lamson)   
9          1         0                            Artagaveytia, Mr. Ramon   
10         1         0                             Astor, Col. John Jacob   
"""

pd.read_csv(StringIO(txt), sep="\s{2,}", header=0, index_col=0, engine='python')

    pclass  survived                                             name
0        1         1                    Allen, Miss. Elisabeth Walton
1        1         1                   Allison, Master. Hudson Trevor
2        1         0                     Allison, Miss. Helen Loraine
3        1         0             Allison, Mr. Hudson Joshua Creighton
4        1         0  Allison, Mrs. Hudson J C (Bessie Waldo Daniels)
5        1         1                              Anderson, Mr. Harry
6        1         1                Andrews, Miss. Kornelia Theodosia
7        1         0                           Andrews, Mr. Thomas Jr
8        1         1    Appleton, Mrs. Edward Dale (Charlotte Lamson)
9        1         0                          Artagaveytia, Mr. Ramon
10       1         0                           Astor, Col. John Jacob

Upvotes: 3

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