Question

Discuss what happens when strings are concatenated together within the computer's memory.

Describe any ideas on how to make the concatenation process as fast as possible considering the immutability of strings.

this is for fundamentalls of programming and logic and current topics are arround python programing I need help answering these questions as we have no text books.

Answer 1

When strings are concatenated together within the computer's memory

Explanation:  String datatype is immutable in python that means it cannot be changed in place memory location. Any changes to string allocate a new memory location. Due to immutable nature string concatenation operation is memory intensive.

For given example string str

str = "hi"
str += ", there!"

CPython interpreter executes string concatenation code, conceptually it performs below set of task

1. Allocate memory buffer for variable string "hi" 2 bytes => len("hi") + 1, and copy the value into it
2. Datatype string variable str reference value "hi"3.
3. Allocate a new memory with size 11 bytes => len("hi") + len(", there") + 1
4. Later copy "hi", then ", there" into new memory buffer, and variable str reference it
5. Finally it dispose-decrement reference on the old buffer memory string, eventually memory is release.

Ideas to make the concatenation process as fast as possible considering the immutablility of strings

Explanation:

There are many out of the box and custom way to optimize or call string concatenation as per the size of operation. Some of them are listed below. Careful every version of python gives you different set of performance response time throughoutput

1. simple concatenation-->:( s1 += s2)
2. MutableString --> (s1 += s2, where s1 is a MutableString)
3. Append string using sizable array of char
4. Constructing a collection of strings, then invoke .join()
5. Write IO operation using cStringIO memory alloc buffer with in build method write()
6. List comprehension Inline method using join

Based on code execution analysis List comprehension inline method is much faster when run on test data for large string data sets. It is O(1) operation takes one cpu cycle to perform the task as compare to other immutable operations which consume time on memory and cpu cylce.

''.join(str for str in largeStringList)