Help understanding some python syntax

[kevinlyfellow]

Sorry about having to post on a forum for this, but I have no clue how else to find an answer.

Anyways, the question. What does n /= x mean and what does x += x % 2 + 1 mean? I'm unfamiliar with /= and += and I don't know where to find the info.

[tac-tics]

> Sorry about having to post on a forum for this, but I have no clue how else to find an answer.

This seems like a good enough place. You can also try:

http://groups.google.com/group/comp.lang.python/topics

For help in Python


> Anyways, the question. What does n /= x mean and what does x += x % 2 + 1 mean? I'm unfamiliar with /= and += and I don't know where to find the info.

+=, -=, /=, *=, %= are common shorthands in Python, Java, C, and many, many other languages.

They are simply abbreviations, defined as follows:

x += a ==========> x = x + a
x /= a ==========> x = x % a

So
x /= 2, for example, simply halves the value of the variable x.
x += 1, increments the value of variable x by one (in Java and C, you can do x++ for this but not in Python).
x *= x, squares the value of the variable x.

The difference between x + a and x += b is that the first simply __returns__ the value of x + a and the second actually stores that returned value in the variable x. Very handy from time to time.

[kevinlyfellow]

thanks very much :-)

[Billy the Kid]

In Python, "/=" means that the number in front of the operator divided by the number after the operator, equals the variable after the operator.

n = n / x

For example:
a = 36
b = 12
a /= b
# a is equal to 3

In answer to your second question, x is equal to it's current value and the sum of x % (modulus) 2 + 1

Hope that helps

[kevinlyfellow]

In Python, "/=" means that the number in front of the operator divided by the number after the operator, equals the variable after the operator.

n = n / x

For example:
a = 36
b = 12
a /= b
# a is equal to 3

In answer to your second question, x is equal to it's current value and the sum of x % (modulus) 2 + 1

Hope that helps

Tac-tics already deconfused me (I caught his error i /= x is the same as i = i/x not i = i % x), but thanks for the effort. I've made quite a bit of progress today! :-)