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Python read text file columnwise


On 2019-01-15, Juris __ <dev_20192019 at outlook.com> wrote:
> Hi!
>
> On 15/01/2019 17:04, Neil Cerutti wrote:
>> On 2019-01-11, shibashibani at gmail.com <shibashibani at gmail.com> wrote:
>>> Hello
>>>>
>>>> I'm very new in python. I have a file in the format:
>>>>
>>>> 2018-05-31   16:00:00        28.90   81.77   4.3
>>>> 2018-05-31   20:32:00        28.17   84.89   4.1
>>>> 2018-06-20   04:09:00        27.36   88.01   4.8
>>>> 2018-06-20   04:15:00        27.31   87.09   4.7
>>>> 2018-06-28   04.07:00        27.87   84.91   5.0
>>>> 2018-06-29   00.42:00        32.20   104.61  4.8
>>>
>>> I would like to read this file in python column-wise.
>>>
>>> I tried this way but not working ....
>>>    event_list = open('seismicity_R023E.txt',"r")
>>>      info_event = read(event_list,'%s %s %f %f %f %f\n');
>> 
>> If it's really tabular data in fixed-width columns you can read
>> it that way with Python.
>> 
>> records = []
>> for line in file:
>>      record = []
>>      i = 0
>>      for width in (30, 8, 7, 5): # approximations
>>          item = line[i:i+width]
>>          record.append(item)
>>          i += width
>>      records.append(record)
>> 
>> This leaves them all strings, which in my experience is more
>> convenient in practice. You can convert as you go if you
>> want,though it won't look nice and simple any longer.
>>
>
> Perhaps even better approach is to use csv module from standard library:
>
> import csv
>
> csv_reader = csv.reader(file, dialect="excel-tab")
> for row in csv_reader:
>      # do something with record data which is conveniently parsed to list
>      print(row)
>
> ['2018-05-31', '16:00:00', '28.90', '81.77', '4.3']
> ...
> ['2018-06-29', '00.42:00', '32.20', '104.61', '4.8']

Yes, if applicable it is awesome!

-- 
Neil Cerutti