Python:如何使用二进制值编码DNA序列?

时间:2016-02-21 07:39:25

标签: python encoding sequence bioinformatics biopython

我想将包含少量DNA序列的文件转换为二进制值,如下所示:

A=1000
C=0100
G=0010
T=0001

FileA.txt

CCGAT
GCTTA

所需的输出

01000100001010000001
00100100000100011000

我已经尝试使用此代码来解决我的问题,但bin输出文件似乎无法输出我想要的答案。任何人都可以帮助我吗?

代码

import sys

if len(sys.argv) != 2 :
  sys.stderr.write('Usage: {} <nucleotide file>\n'.format(sys.argv[0]))
  sys.exit()

# assumes the file only contains dna and newlines
sequence = ''
for line in open(sys.argv[1]) :
  sequence += line.strip().upper()

sequence = sequence.replace('A', chr(0b1000))
sequence = sequence.replace('C', chr(0b0100))
sequence = sequence.replace('G', chr(0b0010))
sequence = sequence.replace('T', chr(0b0001))

outfile = open(sys.argv[1] + '.bin', 'wb')

outfile.write(bytearray(sequence, encoding = 'utf-8'))

2 个答案:

答案 0 :(得分:3)

import re

d = {'A' :'1000','C' : '0100','G':'0010','T': '0001'}

patterns = ['CCGAT' ,'GCTTA']

for p in patterns:
    for c in p:
        p = re.sub(c,d[c],p)
    print(p)

答案 1 :(得分:1)

你想要ascii输出还是二进制?以下内容将为您提供您在帖子中显示的内容(尽管在一行中。代码需要修改以保留换行符。)

import sys

if len(sys.argv) != 2 :
  sys.stderr.write('Usage: {} <nucleotide file>\n'.format(sys.argv[0]))
  sys.exit()

# assumes the file only contains dna and newlines
sequence = ''
for line in open(sys.argv[1]) :
  sequence += line.strip().upper()

sequence = sequence.replace('A', '1000')
sequence = sequence.replace('C', '0100')
sequence = sequence.replace('G', '0010')
sequence = sequence.replace('T', '0001')

outfile = open(sys.argv[1] + '.bin', 'wb')

outfile.write(sequence)

编辑这会创建一个二进制文件,其中每个核苷酸都是一个字节,换行符以二进制格式保存。

import sys

if len(sys.argv) != 2 :
  sys.stderr.write('Usage: {} <nucleotide file>\n'.format(sys.argv[0]))
  sys.exit()

# assumes the file only contains dna and newlines
newbytearray=bytearray(b'',encoding='utf-8')
dict={'A':0b1000,'C':0b0100,'G':0b0010,'T':0b0001,'\n':0b1010}
with open(sys.argv[1]) as file:
    while True:
        char=file.read(1)
        if not char:
            file.close()
            break
        newbytearray.append(dict[char])
outfile = open(sys.argv[1] + '.bin', 'wb')
outfile.write(newbytearray)
outfile.close()

#Converts the binary file to unicode and prints the result sequence.
testBin = open('fileA.txt.bin','rb')
sequence=''
for line in testBin:
    line = line.replace(chr(0b1000),'1000')
    line = line.replace(chr(0b0100),'0100')
    line = line.replace(chr(0b0010),'0010')
    line = line.replace(chr(0b0001),'0001')
    line = line.replace(chr(0b1010),'\n')
    sequence += line
#outputVerify = open('outputVerify.txt','wb')
#outputVerify.write(sequence)
#outputVerify.close()
print sequence
testBin.close()

#Shows the data of the binary file. Note that byte 6 is the newline character 0b1010.
testBin = open('fileA.txt.bin','rb')
list = ''
i=0
while True:
    b = testBin.read(1)
    i += 1
    if not b:
    break #due to eof
    list += b
    print 'byte: ' + str(i) + ' is '+ '{0:04b}'.format(ord(b)) +' and has decimal representation: ' + str(ord(b))
testBin.close()