Python Simple Python Debugging with Pdb: Part 2 - Comments

  • Thread starter Mark44
  • Start date
Mark, how would you compare Python with other similar languages?
 
32,107
3,992
Mark, how would you compare Python with other similar languages?
Python is in some respects similar to C, but is a language that is significantly higher in level. Without using any external libraries/modules, you can get permutations and combinations very quickly.

A couple of the features of Python that distinguish it from C and the languages that derive from C are the map() function and list comprehension. map() returns an iterator that will apply some operator to one or more lists (depending on the operator). In the example below, corresponding pairs of numbers are multiplied in two lists to form a new list that contains these products, and then the sum() function is applied to the list to add all of the numbers. In short, the one-line body of the dotprod() function calculates the dot product of the two lists that are in its argument list. Lower-level languages such as C will typically use a for loop to iterate through the lists.


Python:
# dotprod.py -- find the dot product of two vectors
import operator

def dotprod(u, v):
   return sum(map(operator.mul, u, v))

u = [1, 2, -1, 4, 2, 1, -2, 6]
v = [1, 4, -1, 0, 1, 1, -2, 4]

ans = dotprod(u, v)
print("Result is: ", ans)
This code displays 41 as its result.

List comprehension is "A compact way to process all or part of the elements in a sequence and return a list with the results."
Here's an example that works with the list [0, 1, ..., 255] and creates a new list with only the list elements that are evenly divisible by 16.
Python:
#list_comp.py -- simple example of list comprehension
my_list = [x for x in range(256) if x % 16 == 0]
print(my_list)
The print() statement displays the list as [0, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 240]

I'm sure there are quite a few more differences, but these are just a few that come to mind.
 

Want to reply to this thread?

"Simple Python Debugging with Pdb: Part 2 - Comments" You must log in or register to reply here.

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving

Top Threads

Top