Trouble with for loop

S

Shriphani

Hello,
I want to try something like:

for (a, b, c, d, e, f) in [1, 2, 3, 4, 5, 6, 7, 8, 9]:
####

When I do that I get an error:
TypeError: unpack non-sequence

My main intention is to state that each of the variables namely a, b,
c, ## can take value from 1 to 9.
How do I go about this ?

Regards,
Shriphani Palakodety
 
A

Ant

My main intention is to state that each of the variables namely a, b,
c, ## can take value from 1 to 9.
How do I go about this ?

It sounds like you are after something like:

for var in (a, b, c, d, e, f):
assert var in [1, 2, 3, 4, 5, 6, 7, 8, 9]

but it's hard to tell without some more information from you on
exactly what you are trying to achieve.
 
P

Paul Hankin

Shriphani said:
Hello,
I want to try something like:

for (a, b, c, d, e, f) in [1, 2, 3, 4, 5, 6, 7, 8, 9]:
####

When I do that I get an error:
TypeError: unpack non-sequence

My main intention is to state that each of the variables namely a, b,
c, ## can take value from 1 to 9.
How do I go about this ?

Do you want the variables to be indepenedent?

for a in range(1, 10):
for b in range(1, 10):
for c in range(1, 10):
for d in range(1, 10):
for e in range(1, 10):
for f in range(1, 10):
####

Or all the same?
for a in range(1, 10):
b = c = d = e = f = a

Whatever you're doing though, there's almost certainly a better way.
 
A

Amit Khemka

Hello,
I want to try something like:

for (a, b, c, d, e, f) in [1, 2, 3, 4, 5, 6, 7, 8, 9]:
####

When I do that I get an error:
TypeError: unpack non-sequence

My main intention is to state that each of the variables namely a, b,
c, ## can take value from 1 to 9.
How do I go about this ?

An ugly code for it would be ;-) :
<code>
for (a, b, c, d, e, f) in zip(*[range(1, 10)]*6):
print a, b, c, d, e, f
</code>

Cheers,
 
S

Shriphani

My main intention is to state that each of the variables namely a, b,
c, ## can take value from 1 to 9.
How do I go about this ?

It sounds like you are after something like:

for var in (a, b, c, d, e, f):
assert var in [1, 2, 3, 4, 5, 6, 7, 8, 9]

but it's hard to tell without some more information from you on
exactly what you are trying to achieve.

I want to obtain a number whose first digit "a" is divisible by 1,
10*b +a is divisible by 2, 10^2*c + 10b + a is divisible by 3 and so
on.
I hope my question is a bit clearer now.
Thanks,
Shriphani Palakodety
 
P

Paul Hankin

It sounds like you are after something like:
for var in (a, b, c, d, e, f):
assert var in [1, 2, 3, 4, 5, 6, 7, 8, 9]
but it's hard to tell without some more information from you on
exactly what you are trying to achieve.

I want to obtain a number whose first digit "a" is divisible by 1,
10*b +a is divisible by 2, 10^2*c + 10b + a is divisible by 3 and so
on.
I hope my question is a bit clearer now.

Any time you want a bunch of variables with similar meanings, use an
list (or an array in most other languages) instead. It makes it
clearer what the relationship between the variables is, and it also
makes it much easier to extend the code (for instance, what if you
want to add another digit?)

a + 10*b == 0 (mod 2) => a is even
a + 10*b + ... + 10^4*e == 0 (mod 5) => a is 0 or 5

Therefore, a is 0, so only considering digits 1-9 is a mistake.

So, something like this is probably what you want...

for n in range(10 ** 5, 10 ** 6):
digits = map(int, str(n))
... test digits
 
B

Boris Borcic

Shriphani said:
My main intention is to state that each of the variables namely a, b,
c, ## can take value from 1 to 9.
How do I go about this ?
It sounds like you are after something like:

for var in (a, b, c, d, e, f):
assert var in [1, 2, 3, 4, 5, 6, 7, 8, 9]

but it's hard to tell without some more information from you on
exactly what you are trying to achieve.

I want to obtain a number whose first digit "a" is divisible by 1,
10*b +a is divisible by 2, 10^2*c + 10b + a is divisible by 3 and so
on.

And so on ? up to how many digits ?

10^3 is divisible by 4 and 10^4 is divisible by 5 so that the conditions
on the fourth and fifth digits boil down to 10^2*c+10b+a being divisible
by 4 and 5 in supplement to 3, iow divisible by 60. This implies a==0 but you
seem to say that a must be in [1, 2, 3, 4, 5, 6, 7, 8, 9].

I hope my question is a bit clearer now.

Not really :)
 

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