Another Visit To String Formatting (Python)

Print a simple table using the string format function ...

''' format_table101.py
an example of a table created with format()
'''

# name,age,weight lines read from a csv file
data_str = """\
Heidi Kalumpa,36,127
Frank Maruco,27,234
Larry Pestraus,19,315
Serge Romanowski,59,147
Carolus Arm,94,102
Michel Sargnagel,21,175"""

# create a list of [name, age, weight] lists
data_list = [line.split(',') for line in data_str.split('\n')]
#print(data_list)  # test

# header list
header = ['Name', 'Age', 'Weight']

sf = "{:<18s} {:>6s} {:>7s}"
print(sf.format(*header))
print('-'*33)
for sublist in data_list:
    # unpack the sublist with *
    print(sf.format(*sublist))
print('-'*33)

''' result ...
Name                  Age  Weight
---------------------------------
Heidi Kalumpa          36     127
Frank Maruco           27     234
Larry Pestraus         19     315
Serge Romanowski       59     147
Carolus Arm            94     102
Michel Sargnagel       21     175
---------------------------------
'''

This example shows how to use the __format__ method to fine tune the format of an instance (here a dice) in formatting statements.

#-*-coding: utf8-*- python 2 or 3
from __future__ import (absolute_import, division,
                        print_function, unicode_literals)
from random import choice
try: chr = unichr
except: pass

class Dice(object):
    _values = (1, 2, 3, 4, 5, 6)
    _symbols = tuple(chr(i) for i in range(9856, 9862))
    def __init__(self, value=1):
        assert value in self._values
        self.value = value

    def roll(self):
        self.value = choice(self._values)

    def __format__(self, spec):
        if spec == 'pic': # picture format (a unicode character)
            return self._symbols[self.value-1]
        elif spec == 'd': # integer format
            return str(self.value)
        elif spec == 'r': # repr
            return 'Dice({})'.format(self.value)
        else: # default case
            return super(Dice, self).__format__(spec)

    def __repr__(self):
        return '{:r}'.format(self)

if __name__ == '__main__':
    for i in range(4):
        d = Dice()
        d.roll()
        print('This dice is {x:r}, its value is {x:d}, its picture is {x:pic}'.format(x=d))

"""my output -->
This dice is Dice(4), its value is 4, its picture is ⚃
This dice is Dice(3), its value is 3, its picture is ⚂
This dice is Dice(2), its value is 2, its picture is ⚁
This dice is Dice(6), its value is 6, its picture is ⚅
"""

Edit: hm unicode dice chars don't show correctly.
Edit: added default case.

@Gribouillis,
dice symbols work fine using Idle and Python34 on a Windows machine.
Thank you for the __format__ method.

Here we use function format() to print out a dictionary as a table ...

''' dict_print_table101.py
use format() to print the contents of a dictionary as a table
adjust the table to maximum length of any key
'''

food_dict = {
'almond milk' : 3.29,
'butter' : 2.90,
'bread' : 1.67,
'cheese' : 4.67,
'peanut butter' : 2.48,
'grape jelly' : 177
}

# find max length of food keys
max_len = max(len(food) for food in food_dict)

# food keys will print in dictionary hash order
for food, price in food_dict.items():
    print("{fd:{mx}} = ${pr:4.2f}".format(
        fd=food, pr=price, mx=max_len))

''' result ...
butter        = $2.90
cheese        = $4.67
almond milk   = $3.29
grape jelly   = $177.00
peanut butter = $2.48
bread         = $1.67
'''

print('-'*30)

# use the dictionary key directly to print one item
sf = "Bread costs ${bread:4.2f}"
print(sf.format(**food_dict))

''' result ...
Bread costs $1.67
'''

Great stuff.
I went through it and saved it for future reference. Great cheat sheet.

Thanks