How do I write data to csv file in columns and rows from a list in python?

Question

everyone.I have a list of lists and I want to write them in a csv file with columns and rows.I have tried the writerows but it isn\'t what I want.An example of my list is th

Answer 1

>>> import csv
>>> with open('test.csv', 'wb') as f:
...     wtr = csv.writer(f, delimiter= ' ')
...     wtr.writerows( [[1, 2], [2, 3], [4, 5]])
...
>>> with open('test.csv', 'r') as f:
...     for line in f:
...         print line,
...
1 2 <<=== Exactly what you said that you wanted.
2 3
4 5
>>>

To get it so that it can be loaded sensibly by Excel, you need to use a comma (the csv default) as the delimiter, unless you are in a locale (e.g. Europe) where you need a semicolon.

Answer 2

import pandas as pd
header=['a','b','v']
df=pd.DataFrame(columns=header)
for i in range(len(doc_list)):
  d_id=(test_data.filenames[i]).split('\\')
  doc_id.append(d_id[len(d_id)-1])
  df['a']=doc_id
print(df.head())
df[column_names_to_be_updated]=np.asanyarray(data)
print(df.head())
df.to_csv('output.csv')

Using pandas dataframe,we can write to csv. First create a dataframe as per the your needs for storing in csv. Then create csv of the dataframe using pd.DataFrame.to_csv() API.

Answer 3

The provided examples, using csv modules, are great! Besides, you can always simply write to a text file using formatted strings, like the following tentative example:

l = [[1, 2], [2, 3], [4, 5]]

out = open('out.csv', 'w')
for row in l:
    for column in row:
        out.write('%d;' % column)
    out.write('\n')
out.close()

I used ; as separator, because it works best with Excell (one of your requirements).

Hope it helps!

Answer 4

Well, if you are writing to a CSV file, then why do you use space as a delimiter? CSV files use commas or semicolons (in Excel) as cell delimiters, so if you use delimiter=' ', you are not really producing a CSV file. You should simply construct csv.writer with the default delimiter and dialect. If you want to read the CSV file later into Excel, you could specify the Excel dialect explicitly just to make your intention clear (although this dialect is the default anyway):

example = csv.writer(open("test.csv", "wb"), dialect="excel")

Answer 5

Have a go with these code:

>>> import pyexcel as pe
>>> sheet = pe.Sheet(data)
>>> data=[[1, 2], [2, 3], [4, 5]]
>>> sheet
Sheet Name: pyexcel
+---+---+
| 1 | 2 |
+---+---+
| 2 | 3 |
+---+---+
| 4 | 5 |
+---+---+
>>> sheet.save_as("one.csv")
>>> b = [[126, 125, 123, 122, 123, 125, 128, 127, 128, 129, 130, 130, 128, 126, 124, 126, 126, 128, 129, 130, 130, 130, 130, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 132, 134, 134, 134, 134, 134, 134, 134, 134, 133, 134, 135, 134, 133, 133, 134, 135, 136], [135, 135, 136, 137, 137, 136, 134, 135, 135, 135, 134, 134, 133, 133, 133, 134, 134, 134, 133, 133, 132, 132, 132, 135, 135, 133, 133, 133, 133, 135, 135, 131, 135, 136, 134, 133, 136, 137, 136, 133, 134, 135, 136, 136, 135, 134, 133, 133, 134, 135, 136, 136, 136, 135, 134, 135, 138, 138, 135, 135, 138, 138, 135, 139], [137, 135, 136, 138, 139, 137, 135, 142, 139, 137, 139, 138, 136, 137, 141, 138, 138, 139, 139, 139, 139, 138, 138, 138, 138, 137, 137, 137, 137, 138, 138, 136, 137, 137, 137, 137, 137, 137, 138, 148, 144, 140, 138, 137, 138, 138, 138, 137, 137, 137, 137, 137, 138, 139, 140, 141, 141, 141, 141, 141, 141, 141, 141, 141], [141, 141, 141, 141, 141, 141, 141, 139, 139, 139, 140, 140, 141, 141, 141, 140, 140, 140, 140, 140, 141, 142, 143, 138, 138, 138, 139, 139, 140, 140, 140, 141, 140, 139, 139, 141, 141, 140, 139, 145, 137, 137, 145, 145, 137, 137, 144, 141, 139, 146, 134, 145, 140, 149, 144, 145, 142, 140, 141, 144, 145, 142, 139, 140]]
>>> s2 = pe.Sheet(b)
>>> s2
Sheet Name: pyexcel
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
| 126 | 125 | 123 | 122 | 123 | 125 | 128 | 127 | 128 | 129 | 130 | 130 | 128 | 126 | 124 | 126 | 126 | 128 | 129 | 130 | 130 | 130 | 130 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 132 | 134 | 134 | 134 | 134 | 134 | 134 | 134 | 134 | 133 | 134 | 135 | 134 | 133 | 133 | 134 | 135 | 136 |
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
| 135 | 135 | 136 | 137 | 137 | 136 | 134 | 135 | 135 | 135 | 134 | 134 | 133 | 133 | 133 | 134 | 134 | 134 | 133 | 133 | 132 | 132 | 132 | 135 | 135 | 133 | 133 | 133 | 133 | 135 | 135 | 131 | 135 | 136 | 134 | 133 | 136 | 137 | 136 | 133 | 134 | 135 | 136 | 136 | 135 | 134 | 133 | 133 | 134 | 135 | 136 | 136 | 136 | 135 | 134 | 135 | 138 | 138 | 135 | 135 | 138 | 138 | 135 | 139 |
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
| 137 | 135 | 136 | 138 | 139 | 137 | 135 | 142 | 139 | 137 | 139 | 138 | 136 | 137 | 141 | 138 | 138 | 139 | 139 | 139 | 139 | 138 | 138 | 138 | 138 | 137 | 137 | 137 | 137 | 138 | 138 | 136 | 137 | 137 | 137 | 137 | 137 | 137 | 138 | 148 | 144 | 140 | 138 | 137 | 138 | 138 | 138 | 137 | 137 | 137 | 137 | 137 | 138 | 139 | 140 | 141 | 141 | 141 | 141 | 141 | 141 | 141 | 141 | 141 |
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
| 141 | 141 | 141 | 141 | 141 | 141 | 141 | 139 | 139 | 139 | 140 | 140 | 141 | 141 | 141 | 140 | 140 | 140 | 140 | 140 | 141 | 142 | 143 | 138 | 138 | 138 | 139 | 139 | 140 | 140 | 140 | 141 | 140 | 139 | 139 | 141 | 141 | 140 | 139 | 145 | 137 | 137 | 145 | 145 | 137 | 137 | 144 | 141 | 139 | 146 | 134 | 145 | 140 | 149 | 144 | 145 | 142 | 140 | 141 | 144 | 145 | 142 | 139 | 140 |
+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
>>> s2[0,0]
126
>>> s2.save_as("two.csv")