Python import csv to list

Question

I have a CSV file with about 2000 records    Each record has a string  and a category to it   This is the first line Line1 This is the second line Line2 This is the third line Line3   I need to read this file into a list that looks like this   data      This is the first line    Line1              This is the second line    Line2              This is the third line    Line3      How can import this CSV to the list I need using Python

User · Answer

Here is the easiest way in Python 3 x to import a CSV to a multidimensional array  and its only 4 lines of code without importing anything    pull a CSV into a multidimensional array in 4 lines   L                                Create an empty list for the main array for line in open  log txt        Open the file and read all the lines     x line rstrip                Strip the  n from each line     L append x split             Split each line into a list and add it to the                                  Multidimensional array print L

User · Answer

Unfortunately I find none of the existing answers particularly satisfying    Here is a straightforward and complete Python 3 solution  using the csv module   import csv  with open     resources temp in csv   newline     as f      reader   csv reader f  skipinitialspace True      rows   list reader   print rows    Notice the skipinitialspace True argument  This is necessary since  unfortunately  OP s CSV contains whitespace after each comma   Output      This is the first line    Line1      This is the second line    Line2      This is the third line    Line3

User · Answer

You can use the list   function to convert csv reader object to list import csv  with open  input csv   as csv file      reader   csv reader csv file  delimiter          rows   list reader      print rows

User · Answer

If you are sure there are no commas in your input  other than to separate the category  you can read the file line by line and split on    then push the result to List  That said  it looks like you are looking at a CSV file  so you might consider using the modules for it

User · Answer

A simple loop would suffice   lines      with open  test txt    r   as f      for line in f readlines            l name   line strip   split              lines append  l name    print lines

User · Answer

Using the csv module   import csv  with open  file csv   newline     as f      reader   csv reader f      data   list reader   print data    Output      This is the first line    Line1      This is the second line    Line2      This is the third line    Line3        If you need tuples   import csv  with open  file csv   newline     as f      reader   csv reader f      data    tuple row  for row in reader   print data    Output      This is the first line    Line1      This is the second line    Line2      This is the third line    Line3        Old Python 2 answer  also using the csv module   import csv with open  file csv    rb   as f      reader   csv reader f      your list   list reader   print your list      This is the first line    Line1         This is the second line    Line2         This is the third line    Line3

User · Answer

Extending your requirements a bit and assuming you do not care about the order of lines and want to get them grouped under categories  the following solution may work for you    gt  gt  gt  fname    lines txt   gt  gt  gt  from collections import defaultdict  gt  gt  gt  dct   defaultdict list   gt  gt  gt  with open fname  as f          for line in f              text  cat   line rstrip   n   split      1              dct cat  append text       gt  gt  gt  dct defaultdict  lt type  list  gt      CatA     This is the first line    This is the another line      CatC     This is the third line      CatB     This is the second line    This is the last line       This way you get all relevant lines available in the dictionary under key being the category

User · Answer

Next is a piece of code which uses csv module but extracts file csv contents to a list of dicts using the first line which is a header of csv table  import csv def csv2dicts filename     with open filename   rb   as f      reader   csv reader f      lines   list reader      if len lines   lt  2  return None     names   lines 0      if len names   lt  1  return None     dicts          for values in lines 1          if len values     len names   return None       d            for i   in enumerate names           d names i     values i        dicts append d      return dicts   return None  if   name         main       your list   csv2dicts  file csv     print your list

User · Answer

Update for Python3   import csv from pprint import pprint  with open  text csv   newline     as file      reader   csv reader file      res   list map tuple  reader    pprint res    Output      This is the first line     Line1       This is the second line     Line2       This is the third line     Line3      If csvfile is a file object  it should be opened with newline     csv module

User · Answer

As said already in the comments you can use the csv library in python  csv means comma separated values which seems exactly your case  a label and a value separated by a comma   Being a category and value type I would rather use a dictionary type instead of a list of tuples   Anyway in the code below I show both ways  d is the dictionary and l is the list of tuples   import csv  file name    test txt  try      csvfile   open file name   rt   except      print  File not found   csvReader   csv reader csvfile  delimiter      d   dict   l    list   for row in csvReader      d row 1     row 0      l append  row 0   row 1    print d  print l

User · Answer

Pandas is pretty good at dealing with data  Here is one example how to use it   import pandas as pd    Read the CSV into a pandas data frame  df      With a df you can do many things     most important  visualize data with Seaborn df   pd read csv  filename csv   delimiter         Or export it in many ways  e g  a list of tuples tuples    tuple x  for x in df values     or export it as a list of dicts dicts   df to dict   values     One big advantage is that pandas deals automatically with header rows   If you haven t heard of Seaborn  I recommend having a look at it   See also  How do I read and write CSV files with Python    Pandas  2  import pandas as pd    Get data - reading the CSV file import mpu pd df   mpu pd example df      Convert dicts   df to dict  records     The content of df is        country   population population time    EUR 0    Germany   82521653 0      2016-12-01   True 1     France   66991000 0      2017-01-01   True 2  Indonesia  255461700 0      2017-01-01  False 3    Ireland    4761865 0             NaT   True 4      Spain   46549045 0      2017-06-01   True 5    Vatican          NaN             NaT   True   The content of dicts is     country    Germany    population   82521653 0   population time   Timestamp  2016-12-01 00 00 00     EUR   True      country    France    population   66991000 0   population time   Timestamp  2017-01-01 00 00 00     EUR   True      country    Indonesia    population   255461700 0   population time   Timestamp  2017-01-01 00 00 00     EUR   False      country    Ireland    population   4761865 0   population time   NaT   EUR   True      country    Spain    population   46549045 0   population time   Timestamp  2017-06-01 00 00 00     EUR   True      country    Vatican    population   nan   population time   NaT   EUR   True     Pandas  3  import pandas as pd    Get data - reading the CSV file import mpu pd df   mpu pd example df      Convert lists     row col  for col in df columns  for row in df to dict  records      The content of lists is      Germany   82521653 0  Timestamp  2016-12-01 00 00 00    True      France   66991000 0  Timestamp  2017-01-01 00 00 00    True      Indonesia   255461700 0  Timestamp  2017-01-01 00 00 00    False      Ireland   4761865 0  NaT  True      Spain   46549045 0  Timestamp  2017-06-01 00 00 00    True      Vatican   nan  NaT  True

User · Answer

result      for line in text splitlines        result append tuple line split

User · Answer

Updated for Python 3   import csv  with open  file csv   newline     as f      reader   csv reader f      your list   list reader   print your list    Output      This is the first line    Line1      This is the second line    Line2      This is the third line    Line3

[python] Python import csv to list

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