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HHMathewChan
HHMathewChan

Posted on • Updated on

Python daily exercise 3: reverse a string

#python #beginners #string

Question

  • write a program to reverse a given string 
str1 = "PYnative"
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  • Expected output 
evitanYP
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My attempt 

str1 = "PYnative"
reversed_string = str1[::-1]
print(reversed_string)
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Recommend solution 

str1 = "PYnative"
print("Original String is:", str1)

str1 = ''.join(reversed(str1))
print("Reversed String is:", str1)
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My reflection

I only know how to reversed a string using string slicing method, but do not know the reverse() and the join().

Top comments (2)

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jmagave profile image
jmagave •

Looks like using slice is 4x faster. Timed with %timeit command of YPython.

%timeit s[::-1]
81 ns ± 1.05 ns per loop (mean ± std. dev. of 7 runs, 10000000 loops each)
%timeit "".join(reversed(s))
311 ns ± 2.89 ns per loop (mean ± std. dev. of 7 runs, 1000000 loops each)
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mathewchan profile image
HHMathewChan •

just find out your comment, good to know how to count program time, thx

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