How can I multiply all items in a list together with Python?
I need to write a function that takes a list of numbers and multiplies them together. Example: [1,2,3,4,5,6] will give me 1*2*3*4*5*6. I could really use your help. 17 Answers 17
multiplication
Is multiplication and division using shift operators in C actually faster?
Multiplication and division can be achieved using bit operators, for example i*2 = i<<1 i*3 = (i<<1) + i; i*10 = (i<<3) + (i<<1) and so on. Is it actually faster to use say (i<<3)+(i<<1) to multiply with 10 than using i*10 directly? Is there any sort of input that can’t be multiplied or divided … Read more
Extracting bits with a single multiplication
I saw an interesting technique used in an answer to another question, and would like to understand it a little better. We’re given an unsigned 64-bit integer, and we are interested in the following bits: 1…….2…….3…….4…….5…….6…….7…….8……. Specifically, we’d like to move them to the top eight positions, like so: 12345678……………………………………………….. We don’t care about the … Read more
Create list of single item repeated N times
I want to create a series of lists, all of varying lengths. Each list will contain the same element e, repeated n times (where n = length of the list). How do I create the lists, without using a list comprehension [e for number in xrange(n)] for each list? 8 s 8 You can also … Read more
