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Python Python Basics (Retired) Ins & Outs String Concatenation

Ali Mammadov
Ali Mammadov
2,172 Points
Posted by Ali Mammadov
Ali Mammadov
2,172 Points

String concatenation performance in Python

Is there a more efficient, in terms of used resources, way to concatenate strings in Python?

2 Answers

Kenneth Love
STAFF
Kenneth Love
Treehouse Guest Teacher
Kenneth Love
Kenneth Love
Treehouse Guest Teacher

Are you just trying to join a bunch of strings together? .join() is probably faster & more memory efficient than +.

That said, string concatenation in Python isn't very inefficient since the GC is pretty solid.

Ali Mammadov
Ali Mammadov
2,172 Points
Ali Mammadov
Ali Mammadov
2,172 Points

Are there any alternatives to .join()?

Kenneth Love
Kenneth Love
Treehouse Guest Teacher
Kenneth Love
Kenneth Love
Treehouse Guest Teacher

Not really. You could do it the slower and concatenation way.

final_string = ''
for string in list_of_strings:
    final_string += string

Are you really in a position where you need to optimize this? If you're not, don't waste time on it.

Ali Mammadov
Ali Mammadov
2,172 Points
Ali Mammadov
Ali Mammadov
2,172 Points

Believe me, I am! I have came to a few versions. How do you think, which of them will be the fastest?

cdmp = "%(BIN)s%(CC)s%(EXP)s%(HLDR)s" % locals()

cdmp = "{BIN}{CC}{EXP}{HLDR}".format(**locals())

parts = []
for CRD in avg_dmp:
    avg_dmp.append(rtvr_nums(CRD))
cdmp = "".join(avg_dmp)
Vittorio Somaschini
Vittorio Somaschini
33,371 Points
Vittorio Somaschini
Vittorio Somaschini
33,371 Points

Hello Ali.

I think that is the way to do concatenation in Python, but in the following videos you will discover a way to put variables inside strings using placeholders and .format().

I am pretty sure you will like it!

;)

Ali Mammadov
Ali Mammadov
2,172 Points
Ali Mammadov
Ali Mammadov
2,172 Points

But string concatenation eats a lot of memory, because it creates useless duplicates of strings in RAM. How can I get rid of this? I'm trying to concatenate pretty big strings (>500 characters each).