Python Forum

import random
r1 =(random.randrange(0, 3))
r2 =(random.randrange(0, 3))
r3 =(random.randrange(0, 3))
num1=111
num2=222
num3=333
text1 = "numbers: {r1},{r2},{r3}" # error in this line
print(text1.format(num1,num2,num3))

num1=111
num2=222
num3=333
text1 = "numbers: {0},{1},{2}"
print(text1.format(num1,num2,num3))

num1=111
num2=222
num3=333
text1 = "numbers: {2},{1},{0}"
print(text1.format(num1,num2,num3))

Output:
numbers: 333,222,111

import random
r1 =(random.randrange(0, 3))
r2 =(random.randrange(3, 6))
r3 =(random.randrange(6, 9))
print(f'numbers: {r1},{r2},{r3}')

(Jan-07-2021, 09:10 PM)deanhystad Wrote: [ -> ]You are confusing .format with f'. This is your example with corrections,

num1=111
num2=222
num3=333
text1 = "numbers: {0},{1},{2}"
print(text1.format(num1,num2,num3))

The numbers in "numbers: {0},{1},{2}" are index numbers and tell the formatter which argument to print where. This will print the numbers in the opposite order.

num1=111
num2=222
num3=333
text1 = "numbers: {2},{1},{0}"
print(text1.format(num1,num2,num3))

Output:
numbers: 333,222,111

The code below uses the newest way to format strings, f-Strings.

import random
r1 =(random.randrange(0, 3))
r2 =(random.randrange(3, 6))
r3 =(random.randrange(6, 9))
print(f'numbers: {r1},{r2},{r3}')

When using f-Strings the brackets contain the thing you want to print instead of an index that is used to get the value from the format() function.

(Jan-07-2021, 09:10 PM)deanhystad Wrote: [ -> ]You are confusing .format with f'. This is your example with corrections,

num1=111
num2=222
num3=333
text1 = "numbers: {0},{1},{2}"
print(text1.format(num1,num2,num3))

The numbers in "numbers: {0},{1},{2}" are index numbers and tell the formatter which argument to print where. This will print the numbers in the opposite order.

num1=111
num2=222
num3=333
text1 = "numbers: {2},{1},{0}"
print(text1.format(num1,num2,num3))

Output:
numbers: 333,222,111

The code below uses the newest way to format strings, f-Strings.

import random
r1 =(random.randrange(0, 3))
r2 =(random.randrange(3, 6))
r3 =(random.randrange(6, 9))
print(f'numbers: {r1},{r2},{r3}')

When using f-Strings the brackets contain the thing you want to print instead of an index that is used to get the value from the format() function.

# random color
import random
r1 =(random.randrange(0, 3))
r2 =(random.randrange(0, 3))
r3 =(random.randrange(0, 3))
color1=111 #Red
color2=222 #Yellow
color3=333 #Blue
text1 = "new Color is: {r1},{r2},{r3}"
print(text1.format(color1,color2,color3))

print("{0} {1} {2}".format('a', 'b', 'c')
        ^   ^   ^           |    |    |
        |   |   |           |    |    |
        ----|---|------------    |    |
            ----|-----------------    |
                -----------------------

Output:
a b c

[python]print("{} {} {}".format('a', 'b', 'c')

Output:
a b c

# random color
import random
colors = (111, 222, 333)
new_color = random.choices(colors, k=3)
text1 = "new Color is: {0},{1},{2}"
print(text1.format(*new_color))

# random color
import random
positions = ('{0}', '{1}', '{2}')
random_positions = random.choices(positions, k=3)
random_format = "new Color is: {},{},{}".format(*random_positions)
print(random_format) # <- So we can see the format string
print(random_format.format(111, 222, 333)) # <- Using the format string

Output:
new Color is: {1},{0},{2}
new Color is: 222,111,333

# random color
import random
p0 = random.randint(0,2)
p1 = random.randint(0,2)
p2 = random.randint(0,2)
print(p0, p1, p2)
print(f'new Color is {{{p0}}},{{{p1}}},{{{p2}}}'.format(111, 222, 333))

Output:
0 2 2
new Color is 111,333,333

(Jan-07-2021, 11:59 PM)deanhystad Wrote: [ -> ]You are still mixing up the .format with f-String.

If you use .format() then the thing in brackets {0} is an index that says which argument to use in the format string.

print("{0} {1} {2}".format('a', 'b', 'c')
        ^   ^   ^           |    |    |
        |   |   |           |    |    |
        ----|---|------------    |    |
            ----|-----------------    |
                -----------------------

Output:
a b c

You can leave the index values out and they are assumed to be 0, 1, … going from left to right.

[python]print("{} {} {}".format('a', 'b', 'c')

Output:
a b c

When using format you cannot put anything in the brackets except an integer which will be used as an index. You cannot use a variable that contains the index number. Python does not evaluate the things in the brackets when using .format. That only happens with f-Strings

To do what you want I would change the order of the items and leave the format string alone.

# random color
import random
colors = (111, 222, 333)
new_color = random.choices(colors, k=3)
text1 = "new Color is: {0},{1},{2}"
print(text1.format(*new_color))

You can also change the format string, but I think this is really messy and advise against it.

# random color
import random
positions = ('{0}', '{1}', '{2}')
random_positions = random.choices(positions, k=3)
random_format = "new Color is: {},{},{}".format(*random_positions)
print(random_format) # <- So we can see the format string
print(random_format.format(111, 222, 333)) # <- Using the format string

Output:
new Color is: {1},{0},{2}
new Color is: 222,111,333

And if you really want to drive yourself insane you can use .format and f-Strings together like this:

# random color
import random
p0 = random.randint(0,2)
p1 = random.randint(0,2)
p2 = random.randint(0,2)
print(p0, p1, p2)
print(f'new Color is {{{p0}}},{{{p1}}},{{{p2}}}'.format(111, 222, 333))

Output:
0 2 2
new Color is 111,333,333

This is truly horrible, but I think it does what you want and is the solution that is closest to your initial attempt. Those triple brackets are required because double brackets "{{" or "}}" is how you treat a bracket as a normal character.

(Jan-08-2021, 07:31 AM)buran Wrote: [ -> ]Please, don't quote full posts every time. no need of it and it unnecessarily makes you scroll in order to reach the next post.

I don't know if this is intentional or not, but do you realise that you can have repeating "random" positions (i.e. when you do random.randint(0,2) three times in a row, it's possible to get repeating number(s))?