TUTORIAL ON HOW TO USE THE PRETTYTABLE 0.6+ API

*** This tutorial is distributed with PrettyTable and is meant to serve as a "quick start" guide for the lazy or impatient. It is not an exhaustive description of the whole API, and it is not guaranteed to be 100% up to date. For more complete and update documentation, check the PrettyTable wiki at http://code.google.com/p/prettytable/w/list ***

= Getting your data into (and out of) the table =

Let's suppose you have a shiny new PrettyTable:

from prettytable import PrettyTable x = PrettyTable()

and you want to put some data into it. You have a few options.

== Row by row ==

You can add data one row at a time. To do this you can set the field names first using the field_names attribute, and then add the rows one at a time using the add_row method:

x.field_names = ["City name", "Area", "Population", "Annual Rainfall"] x.add_row(["Adelaide",1295, 1158259, 600.5]) x.add_row(["Brisbane",5905, 1857594, 1146.4]) x.add_row(["Darwin", 112, 120900, 1714.7]) x.add_row(["Hobart", 1357, 205556, 619.5]) x.add_row(["Sydney", 2058, 4336374, 1214.8]) x.add_row(["Melbourne", 1566, 3806092, 646.9]) x.add_row(["Perth", 5386, 1554769, 869.4])

== Column by column ==

You can add data one column at a time as well. To do this you use the add_column method, which takes two arguments - a string which is the name for the field the column you are adding corresponds to, and a list or tuple which contains the column data"

x.add_column("City name", ["Adelaide","Brisbane","Darwin","Hobart","Sydney","Melbourne","Perth"]) x.add_column("Area", [1295, 5905, 112, 1357, 2058, 1566, 5386]) x.add_column("Population", [1158259, 1857594, 120900, 205556, 4336374, 3806092, 1554769]) x.add_column("Annual Rainfall",[600.5, 1146.4, 1714.7, 619.5, 1214.8, 646.9, 869.4])

== Mixing and matching ==

If you really want to, you can even mix and match add_row and add_column and build some of your table in one way and some of it in the other. There's a unit test which makes sure that doing things this way will always work out nicely as if you'd done it using just one of the two approaches. Tables built this way are kind of confusing for other people to read, though, so don't do this unless you have a good reason.

== Importing data from a CSV file ==

If you have your table data in a comma separated values file (.csv), you can read this data into a PrettyTable like this:

from prettytable import from_csv fp = open("myfile.csv", "r") mytable = from_csv(fp) fp.close()

== Importing data from a database cursor ==

If you have your table data in a database which you can access using a library which confirms to the Python DB-API (e.g. an SQLite database accessible using the sqlite module), then you can build a PrettyTable using a cursor object, like this:

import sqlite3 from prettytable import from_cursor

connection = sqlite3.connect("mydb.db") cursor = connection.cursor() cursor.execute("SELECT field1, field2, field3 FROM my_table") mytable = from_cursor(cursor)

== Getting data out ==

There are three ways to get data out of a PrettyTable, in increasing order of completeness:

The del_row method takes an integer index of a single row to delete.
The clear_rows method takes no arguments and deletes all the rows in the table - but keeps the field names as they were so you that you can repopulate it with the same kind of data.
The clear method takes no arguments and deletes all rows and all field names. It's not quite the same as creating a fresh table instance, though - style related settings, discussed later, are maintained.

= Displaying your table in ASCII form =

PrettyTable's main goal is to let you print tables in an attractive ASCII form, like this:

+-----------+------+------------+-----------------+ | City name | Area | Population | Annual Rainfall | +-----------+------+------------+-----------------+ | Adelaide | 1295 | 1158259 | 600.5 | | Brisbane | 5905 | 1857594 | 1146.4 | | Darwin | 112 | 120900 | 1714.7 | | Hobart | 1357 | 205556 | 619.5 | | Melbourne | 1566 | 3806092 | 646.9 | | Perth | 5386 | 1554769 | 869.4 | | Sydney | 2058 | 4336374 | 1214.8 | +-----------+------+------------+-----------------+

You can print tables like this to stdout or get string representations of them.

== Printing ==

To print a table in ASCII form, you can just do this:

print x

in Python 2.x or:

print(x)

in Python 3.x.

The old x.printt() method from versions 0.5 and earlier has been removed.

To pass options changing the look of the table, use the get_string() method documented below:

print x.get_string()

== Stringing ==

If you don't want to actually print your table in ASCII form but just get a string containing what would be printed if you use "print x", you can use the get_string method:

mystring = x.get_string()

This string is guaranteed to look exactly the same as what would be printed by doing "print x". You can now do all the usual things you can do with a string, like write your table to a file or insert it into a GUI.

== Controlling which data gets displayed ==

If you like, you can restrict the output of print x or x.get_string to only the fields or rows you like.

The fields argument to these methods takes a list of field names to be printed:

print x.get_string(fields=["City name", "Population"])

gives:

+-----------+------------+ | City name | Population | +-----------+------------+ | Adelaide | 1158259 | | Brisbane | 1857594 | | Darwin | 120900 | | Hobart | 205556 | | Melbourne | 3806092 | | Perth | 1554769 | | Sydney | 4336374 | +-----------+------------+

The start and end arguments take the index of the first and last row to print respectively. Note that the indexing works like Python list slicing - to print the 2nd, 3rd and 4th rows of the table, set start to 1 (the first row is row 0, so the second is row 1) and set end to 4 (the index of the 4th row, plus 1):

print x.get_string(start=1,end=4)

prints:

+-----------+------+------------+-----------------+ | City name | Area | Population | Annual Rainfall | +-----------+------+------------+-----------------+ | Brisbane | 5905 | 1857594 | 1146.4 | | Darwin | 112 | 120900 | 1714.7 | | Hobart | 1357 | 205556 | 619.5 | +-----------+------+------------+-----------------+

== Changing the alignment of columns ==

By default, all columns in a table are centre aligned.

=== All columns at once ===

You can change the alignment of all the columns in a table at once by assigning a one character string to the align attribute. The allowed strings are "l", "r" and "c" for left, right and centre alignment, respectively:

x.align = "r" print x

gives:

=== One column at a time ===

You can also change the alignment of individual columns based on the corresponding field name by treating the align attribute as if it were a dictionary.

x.align["City name"] = "l" x.align["Area"] = "c" x.align["Population"] = "r" x.align["Annual Rainfall"] = "c" print x

gives:

== Sorting your table by a field ==

You can make sure that your ASCII tables are produced with the data sorted by one particular field by giving get_string a sortby keyword argument, which must be a string containing the name of one field.

For example, to print the example table we built earlier of Australian capital city data, so that the most populated city comes last, we can do this:

print x.get_string(sortby="Population")

to get

+-----------+------+------------+-----------------+ | City name | Area | Population | Annual Rainfall | +-----------+------+------------+-----------------+ | Darwin | 112 | 120900 | 1714.7 | | Hobart | 1357 | 205556 | 619.5 | | Adelaide | 1295 | 1158259 | 600.5 | | Perth | 5386 | 1554769 | 869.4 | | Brisbane | 5905 | 1857594 | 1146.4 | | Melbourne | 1566 | 3806092 | 646.9 | | Sydney | 2058 | 4336374 | 1214.8 | +-----------+------+------------+-----------------+

If we want the most populated city to come first, we can also give a reversesort=True argument.

If you always want your tables to be sorted in a certain way, you can make the setting long term like this:

x.sortby = "Population" print x print x print x

All three tables printed by this code will be sorted by population (you could do x.reversesort = True as well, if you wanted). The behaviour will persist until you turn it off:

x.sortby = None

If you want to specify a custom sorting function, you can use the sort_key keyword argument. Pass this a function which accepts two

Prettytable

Install / Use

README