我想使用python提取并打印每个块的第一行中包含10917、11396和1116920的块

Question

Each block starts with hg19 and ends with the white space. Can I use regular expressions to extract the required blocks?

hg19.chr1 10917 479
panTro2.chr15 13606 455

hg19.chr1 11396 93
panTro2.chr15 14061 42
bosTau4.chr5 113864279 105

hg19.chr1 11489 81
panTro2.chr15 14103 81
bosTau4.chr5 113864398 80
equCab2.chr6 54105327 83
canFam2.chr27 45128907 82
calJac1.Contig8673 78513 67

hg19.chr1 1116920 38
panTro2.chr1 1103202 38
gorGor1.Supercontig_0004540 23214 38
ponAbe2.chr1 534356 38
papHam1.scaffold19767 38455 38
calJac1.Contig4288 217257 29
micMur1.scaffold_101519 296 37
dipOrd1.scaffold_7421 49811 22
cavPor3.scaffold_186 248497 22
bosTau4.chr16 29320296 47
equCab2.chr2 72413055 53
felCat3.scaffold_124042 293309 9

hg19.chr1 1116863 57
papHam1.scaffold19767 38399 56
ponAbe2.chr1 534300 56


and so on...

I've tried doing with various regular expressions, but wasn't successful.

Answer 1

The following will read your data from a file called input.txt . It then creates a list containing all of the blocks. It then filters this list to only contain the required entries and then displays them:

import re

with open('input.txt') as f_input:
    data = f_input.read()
    blocks = re.findall(r'(^hg19\..*?)\n*?(?=^hg19\.|\Z)', data, re.S + re.M)

allowed = set(["10917", "11396", "1116920"])
blocks = [block for block in blocks if block.split('\n', 1)[0].split()[1] in allowed]

for block in blocks:
    print block
    print '----'

This would display the following:

hg19.chr1 10917 479
panTro2.chr15 13606 455
----
hg19.chr1 11396 93
panTro2.chr15 14061 42
bosTau4.chr5 113864279 105
----
hg19.chr1 1116920 38
panTro2.chr1 1103202 38
gorGor1.Supercontig_0004540 23214 38
ponAbe2.chr1 534356 38
papHam1.scaffold19767 38455 38
calJac1.Contig4288 217257 29
micMur1.scaffold_101519 296 37
dipOrd1.scaffold_7421 49811 22
cavPor3.scaffold_186 248497 22
bosTau4.chr16 29320296 47
equCab2.chr2 72413055 53
felCat3.scaffold_124042 293309 9
----

This assumes that your file is small enough to comfortably fit into memory at once. Tested using Python 2.7.6