提取Genebank文件的检索号和碱基序列

1.在NCBI的Genebank子库nucletide下检索gene:IL10,下载Genebank格式的文件，命名为IL10_Genebank:

LOCUS       DQ977084                1925 bp    DNA     linear   PRI 14-JUL-2016
DEFINITION  Macaca nemestrina IL10 (IL10) gene, partial cds.
ACCESSION   DQ977084
VERSION     DQ977084.1
KEYWORDS    .
SOURCE      Macaca nemestrina (pig-tailed macaque)
  ORGANISM  Macaca nemestrina
            Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
            Mammalia; Eutheria; Euarchontoglires; Primates; Haplorrhini;
            Catarrhini; Cercopithecidae; Cercopithecinae; Macaca.
REFERENCE   1  (bases 1 to 1925)
  AUTHORS   Nickel,G.C., Tefft,D.L., Goglin,K. and Adams,M.D.
  TITLE     An empirical test for branch-specific positive selection
  JOURNAL   Genetics 179 (4), 2183-2193 (2008)
   PUBMED   18689901
REFERENCE   2  (bases 1 to 1925)
  AUTHORS   Nickel,G.C., Tefft,D.L., Trevarthen,K., Funt,J. and Adams,M.D.
  TITLE     Positive Selection in Transcription Factor Genes on the Human
            Lineage
  JOURNAL   Unpublished
REFERENCE   3  (bases 1 to 1925)
  AUTHORS   Nickel,G.C., Tefft,D.L., Trevarthen,K., Funt,J. and Adams,M.D.
  TITLE     Direct Submission
  JOURNAL   Submitted (31-AUG-2006) Dept. of Genetics, Case Western Reserve
            University, 10900 Euclid Ave, Cleveland, OH 44106, USA
FEATURES             Location/Qualifiers
     source          1..1925
                     /organism="Macaca nemestrina"
                     /mol_type="genomic DNA"
                     /db_xref="taxon:9545"
     gene            <347..>1831
                     /gene="IL10"
     mRNA            <347..>511
                     /gene="IL10"
                     /product="IL10"
     CDS             347..>511
                     /gene="IL10"
                     /codon_start=1
                     /product="IL10"
                     /protein_id="ABM88029.1"
                     /translation="MHSSALLCCLVLLTGVRASPGQGTQSENSCTRFPGNLPHMLRDL
                     RDAFSRVKTFF"
     exon            <347..511
                     /gene="IL10"
                     /number=1
     gap             628..727
                     /estimated_length=unknown
     mRNA            join(<955..1020,1739..>1831)
                     /gene="IL10"
                     /product="IL10"
     CDS             join(<955..1020,1739..1831)
                     /gene="IL10"
                     /codon_start=1
                     /product="IL10"
                     /protein_id="ABM88030.1"
                     /translation="HRFLPCENKSKAVEQVKNAFSKLQEKGVYKAMSEFDIFINYIEA
                     YMTMKIQN"
     exon            955..1020
                     /gene="IL10"
                     /number=4
     gap             1293..1392
                     /estimated_length=unknown
     exon            1739..>1831
                     /gene="IL10"
                     /number=5
ORIGIN      
        1 catgagctgt tctccccagg aaatcaactt tttttaattg agaagctaaa aaattattct
       61 aagagaggta gcccatccta aaaatagctg tgcagaagtt catgttcaac caatcctttt
      121 tgcttacgat gcaaaatttg aaaactaagt ttattagaga ggttagagaa ggaggagctc
      181 taagcagaaa aaatcctgtg ccgggaaacc tgtgattgtg gctttttatg aatgaagagg
      241 cctccctgag cttacaatat aaaaggggga cagagaggtg aaggtctaca catcaggggc
      301 ttgctcttgc aaaaccaaac cacaagacag acttgcaaaa gaaggcatgc acagctcagc
      361 actgctctgt tgcctagtcc tcctgactgg ggtgagggcc agcccaggcc agggcaccca
      421 gtctgagaac agctgcaccc gcttcccagg caacctgcct cacatgcttc gagacctccg
      481 agatgccttc agcagagtga agactttctt tgtgagtatg attccctcct gtgctttctc
      541 tcttcctggg actgcctgaa ctaggcattt tcctggagct ataagaagaa ccctcctcct
      601 gtgcctccac ttccatcccc aacacctnnn nnnnnnnnnn nnnnnnnnnn nnnnnnnnnn
      661 nnnnnnnnnn nnnnnnnnnn nnnnnnnnnn nnnnnnnnnn nnnnnnnnnn nnnnnnnnnn
      721 nnnnnnntcg gagtgggtcc tggagaaata cattttatct cccagggccg tggttcttct
      781 ctgacctttg gatagttagt aagggtgaag cagggctcag ttctctctgg gagctgtgag
      841 gcgaggcatt tggataaatc tagcaccctc atgatgccac cagcttgtcc cccaagtgtg
      901 atggacatgg agctgggagc cgggatcacc aacactttct cttttcttcc acagcatcga
      961 tttcttccct gtgaaaacaa aagcaaggcc gtggagcagg tgaagaatgc ctttagtaag
     1021 gtgagcttgg atggtggcag agagggtctg cagagcacag cccatgccca ctccccaacc
     1081 ccaaagcgtg gaaggtggtg aggactcagt aggccccatc cttcattgga aggagtgtgg
     1141 gaacctgaca gatggtatga cctgctcagc cagtgaggag ctgccgcctt gattgtattt
     1201 gttttctgtt aagtgtcttt gggggtttct aaatgactgc tcgctgcctt tgcaggcttg
     1261 cgggttaggc tggccggcca gcctgtgaac acnnnnnnnn nnnnnnnnnn nnnnnnnnnn
     1321 nnnnnnnnnn nnnnnnnnnn nnnnnnnnnn nnnnnnnnnn nnnnnnnnnn nnnnnnnnnn
     1381 nnnnnnnnnn nngctttcaa agtgcttcct ctaatgtctt ttcatcacac tctgcataat
     1441 catcatgtga atacgtgacc tttaaaattg ttgaaaaggc atcattttga agacagcgct
     1501 ttgcaaaatg aatgctccct ttgctaggca gtagccgtac ttcaggcctg gaggagatga
     1561 aggtcaatgc actgcctttc ccaaggcagc tgggcctatc ctctggttca cttcccagcg
     1621 tgagggagaa taagcagcct ctgcactcaa ggtcatgccc atccatgagc atgggaaagg
     1681 ggagcctatt tcgtccccag aagggattta actgaatgtt tcttatctct ctgcacagct
     1741 ccaagagaaa ggcgtctaca aagccatgag tgagtttgac atcttcatca actacataga
     1801 agcctacatg acaatgaaga tacaaaactg agacatcagg gtggcgactc tatagactct
     1861 aggacataaa ttggaggtct ccaaaatcag atccagggtt ctgggatacc tgacccagcc
     1921 ccttg
//

2.python脚本;

# 提取基因的检索号和碱基序列
input_file = open('IL10_Genebank.gb','r')# 读取Genebank文件
output_file = open('IL10.fasta','w')
flag=0
for line in input_file:
    if line[0:9]=='ACCESSION':
        AC=line.split()[1].strip()
        output_file.write('>'+AC+'\n')
    elif line[0:6]=='ORIGIN':
        flag=1
    elif flag==1:
        fields=line.split()# 以空格为分界，将line转换为list
        if fields!=[]:
            seq=''.join(fields[1:])#将list组装为字符串
            output_file.write(seq.upper()+'\n')
input_file.close()
output_file.close()

3.输出结果

>DQ977084
CATGAGCTGTTCTCCCCAGGAAATCAACTTTTTTTAATTGAGAAGCTAAAAAATTATTCT
AAGAGAGGTAGCCCATCCTAAAAATAGCTGTGCAGAAGTTCATGTTCAACCAATCCTTTT
TGCTTACGATGCAAAATTTGAAAACTAAGTTTATTAGAGAGGTTAGAGAAGGAGGAGCTC
TAAGCAGAAAAAATCCTGTGCCGGGAAACCTGTGATTGTGGCTTTTTATGAATGAAGAGG
CCTCCCTGAGCTTACAATATAAAAGGGGGACAGAGAGGTGAAGGTCTACACATCAGGGGC
TTGCTCTTGCAAAACCAAACCACAAGACAGACTTGCAAAAGAAGGCATGCACAGCTCAGC
ACTGCTCTGTTGCCTAGTCCTCCTGACTGGGGTGAGGGCCAGCCCAGGCCAGGGCACCCA
GTCTGAGAACAGCTGCACCCGCTTCCCAGGCAACCTGCCTCACATGCTTCGAGACCTCCG
AGATGCCTTCAGCAGAGTGAAGACTTTCTTTGTGAGTATGATTCCCTCCTGTGCTTTCTC
TCTTCCTGGGACTGCCTGAACTAGGCATTTTCCTGGAGCTATAAGAAGAACCCTCCTCCT
GTGCCTCCACTTCCATCCCCAACACCTNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
NNNNNNNTCGGAGTGGGTCCTGGAGAAATACATTTTATCTCCCAGGGCCGTGGTTCTTCT
CTGACCTTTGGATAGTTAGTAAGGGTGAAGCAGGGCTCAGTTCTCTCTGGGAGCTGTGAG
GCGAGGCATTTGGATAAATCTAGCACCCTCATGATGCCACCAGCTTGTCCCCCAAGTGTG
ATGGACATGGAGCTGGGAGCCGGGATCACCAACACTTTCTCTTTTCTTCCACAGCATCGA
TTTCTTCCCTGTGAAAACAAAAGCAAGGCCGTGGAGCAGGTGAAGAATGCCTTTAGTAAG
GTGAGCTTGGATGGTGGCAGAGAGGGTCTGCAGAGCACAGCCCATGCCCACTCCCCAACC
CCAAAGCGTGGAAGGTGGTGAGGACTCAGTAGGCCCCATCCTTCATTGGAAGGAGTGTGG
GAACCTGACAGATGGTATGACCTGCTCAGCCAGTGAGGAGCTGCCGCCTTGATTGTATTT
GTTTTCTGTTAAGTGTCTTTGGGGGTTTCTAAATGACTGCTCGCTGCCTTTGCAGGCTTG
CGGGTTAGGCTGGCCGGCCAGCCTGTGAACACNNNNNNNNNNNNNNNNNNNNNNNNNNNN
NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN
NNNNNNNNNNNNGCTTTCAAAGTGCTTCCTCTAATGTCTTTTCATCACACTCTGCATAAT
CATCATGTGAATACGTGACCTTTAAAATTGTTGAAAAGGCATCATTTTGAAGACAGCGCT
TTGCAAAATGAATGCTCCCTTTGCTAGGCAGTAGCCGTACTTCAGGCCTGGAGGAGATGA
AGGTCAATGCACTGCCTTTCCCAAGGCAGCTGGGCCTATCCTCTGGTTCACTTCCCAGCG
TGAGGGAGAATAAGCAGCCTCTGCACTCAAGGTCATGCCCATCCATGAGCATGGGAAAGG
GGAGCCTATTTCGTCCCCAGAAGGGATTTAACTGAATGTTTCTTATCTCTCTGCACAGCT
CCAAGAGAAAGGCGTCTACAAAGCCATGAGTGAGTTTGACATCTTCATCAACTACATAGA
AGCCTACATGACAATGAAGATACAAAACTGAGACATCAGGGTGGCGACTCTATAGACTCT
AGGACATAAATTGGAGGTCTCCAAAATCAGATCCAGGGTTCTGGGATACCTGACCCAGCC
CCTTG