Complementing a Strand of DNA

a="AGGGCCCCACCAGTACGTCTGGCCAGGGGACTGTGTTAGTGGTGTCGACAGCCGCCACAGGCATAACGATGGATATATACTCCGATACGCATCTCGTAGATTGCCCTATAGGCAGTGGGCAATTAGTAGCGCCCAGTTTTCAAGAGACCTCACGCTCTAGCGAAGCTACGTTTGCCCCCGGGGTGTAAGGGGGCTAAGGTCTACCCGGATCGCGAGGTGGAAGGCCTAAGTAGATCGAATGGTATAAAGGACATCGCATAATAACGTGGAGTGGATCCATCGCACATTACCATTCTGATTACAGTTTTTAATGAATCAATGTTCGGGTTGACCGGGACAAAAATACATGCAGACGATGATAACGCAACTAAATTAACCCCGTTGCAACCTGGTCGCTAGATGACTCCTTTTGATACGAATGCCATTAGTAACGTCATCCTGCGCCGAAGGAGTATTTAATGCAATCCGATACTGGTGAGGGTCCAGAAATTCAGCTTCCGATAGAGCACCCGGGTGATCGTCCTACGTTTGTGGATTTGTCGTTGCTGCCGCTTTTAATACGCTTTTCGGAGTATTCAAGAGCCATCGAGGTGTAGGTCCCTTCGATGTCATTTCTATGGACCGAGCGTGGAGGACCACGCGACCGCCAATATTTCCTTTTCCTTAGAGGACACAAGTAGGCTTTAGATGCGACCAACAAGAAGACGAGTGGGTGACCTAGTGCCCATGCCACATCGATGGGGCAAGGCTTTATGATTAATGACCAAGGGGACTGTTGGTGTTGCTACATCGATCAATGTCTGTCTCAATAGCATAGTCGGACGGCGTGTCGTAAGCAAGCTTTATCTATATTGAGAGACGGGCACATAACGGAAAGCACGCCCGTCGTCTGGTCCACCTCTCTTTA"
a= a.translate({ord('A'):'T',ord('T'):'A',ord('G'):'C',ord('C'):'G'})
a= a[::-1]
print(a)

In DNA strings, symbols 'A' and 'T' are complements of each other, as are 'C' and 'G'.

The reverse complement of a DNA string s$s$ is the string sc$s^{\text{c}}$ formed by reversing the symbols of s$s$, then taking the complement of each symbol (e.g., the reverse complement of "GTCA" is "TGAC").

Given: A DNA string s$s$ of length at most 1000 bp.

Return: The reverse complement sc$s^{\text{c}}$ of s$s$.