python read and write csv files 2091 lyzoyj

PYTHON - Read and Write CSV filesJune 2014

[PYTHON] Read and Write CSV filesIt is possible to read and write CSV (comma separated values) files using Python 2.4Distribution. Like most languages, file operations can be done with Python. Writing a CSV filewith Python can be done by importing the CSV module and creating a write object that will beused with the WriteRow Method. Reading a CSV file can be done in a similar way by creating areader object and by using the print method to read the file. As file operations require advancedconcepts, some knowledge of programming with Python is required to read and write the CSV(comma separated values) files.

PrerequisitesWriting a CSV fileReading a CSV file

Python Www.python.org, version 2.4 supports the de facto CSV format (comma-separatedvalues: ). The Reference Library is very helpful when learning to use Python. Here are someadditional tips to get you started.

Prerequisites

-> Knowledge of Python -> Python 2.4 Distribution

Writing a CSV fileStart by importing the CSV module:import csvWe will define an object "writer" (named c), which can later be used to write the CSV file.c = csv.writer(open("MYFILE.csv", "wb"))Now we will apply the method to write a row. Writerow The method takes one argument - thisargument must be a list and each list item is equivalent to a column. Here, we try to make anaddress book:c.writerow(["Name","Address","Telephone","Fax","E-mail","Others"])Then we will save all entries in this way.

Reading a CSV fileFirst just create an object reader (we will give it a name: cr).cr = csv.reader(open("MYFILE.csv","rb"))And here we get each row (in the form of a list of columns) as follows:for row in cr: print rowWe can of course extract a precise entry of a row with the index:for row in reader: print row[2], row[-2]

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