ImportError: 没有名为writers.SeqRecord.fasta的模块

Question

# File Name RandonProteinSequences.py
# standard library
import os
import random

# biopython
from Bio.Seq import Seq
from Bio.Alphabet import IUPAC
from Bio.SeqRecord import SeqRecord
import Bio.writers.SeqRecord.fasta
from Bio import SeqIO
from sys import *

residueList1 = ["C","D","E","F","G","H","I"]
residueList2 = ["A","K","L","M","N","S"]
residueList3 = ["P","Q","R","T","V","W","Y"]
residueList4 = ["C","A","G","U"]
def getProteinSeqRecord(residue, seqcount):
    strSeq = ""
    for i in range(0,100,1):
        index = random.randint(0, len(residue)-1)
        strSeq += residue[index]

    sequence = Seq(strSeq, IUPAC.IUPACProtein)
    seqRec = SeqRecord(sequence, id = 'randSeq' + str(seqcount), description= 'A random sequence using Amino acid residues.')
    return seqRec

def getProteinSequence(residue):
    strSeq = ""
    for i in range(0,100,1):
        index = random.randint(0, len(residue)-1)
        strSeq += residue[index]

    sequence = Seq(strSeq, IUPAC.IUPACProtein)
    return sequence

def randomProteinSeqRecord(index):
    if(index%2)==0:
        return getProteinSeqRecord(residueList1, index)
    elif(index%3)==0:
        return getProteinSeqRecord(residueList2, index)
    else:
        return getProteinSeqRecord(residueList3, index)

#information
print '--- This is python based program to generate random sequences ---'
print '--- Provide number of random sequences to generate. Default 10 ---'
print '--- Inorder to save to a file provide file path or filename ---'
print '--- If none or invalid filepath is provided then results will be displayed to console ---'
print '--- The file will be created in fasta format ---'
print

filepathProvided = False
#raw_input received the user input as string
try:
    filepath = raw_input('Enter filepath to save sequences ... ')
    filepath = filepath + '.fasta'
    handle = open(filepath, "w")
    handle.close()

    filepathProvided = True
except IOError:
    print 'Invalid or No File provided will print results to console'
print
ranSeqCount = 10
try:
    ranSeqCount = int(raw_input('Enter number of random sequences to generate ... '))
except ValueError:
    ranSeqCount = 10
pass

if(filepathProvided):
    handle = open(filepath, "w")

if(filepathProvided):
    fasta_writer = Bio.writers.SeqRecord.fasta.WriteFasta(handle)
else:
    fasta_writer = Bio.writers.SeqRecord.fasta.WriteFasta(stdout)
print 'Sequence Count : '
print ranSeqCount

for i in range(0,ranSeqCount,1):
    fasta_writer.write(randomProteinSeqRecord(i+1))
if(filepathProvided):
    handle.close()
print 'File created at : ' + filepath

print
raw_input('Press any key to exit ...')
print

出现了这个错误：

错误追踪（最近的调用在最前面）： 文件 "C:\Users\Hemant\Desktop\RandonProteinSequences.py"，第10行，在 import Bio.writers.SeqRecord.fasta 导入错误：没有名为 writers.SeqRecord.fasta 的模块

Answer 1

也许你需要把这部分改成：

import Bio.writers.SeqRecord.fasta

改成：

from Bio.writers.SeqRecord import fasta

Answer 2

我在你之前的问题中已经提到过这个，现在再说一遍：
这段代码需要更新，因为Bio.writers.SeqRecord.fasta已经不再推荐使用。

我快速浏览了一下Biopython的文档，想看看怎么写一个FASTA文件。
你可以试试这个：

# File Name RandonProteinSequences.py
# standard library
import os
import random

# biopython
from Bio.Seq import Seq
from Bio.Alphabet import IUPAC
from Bio.SeqRecord import SeqRecord
from Bio import SeqIO
from sys import *

residueList1 = ["C","D","E","F","G","H","I"]
residueList2 = ["A","K","L","M","N","S"]
residueList3 = ["P","Q","R","T","V","W","Y"]
residueList4 = ["C","A","G","U"]

def getProteinSeqRecord(residue, seqcount):
    strSeq = ""
    for i in range(0,100,1):
        index = random.randint(0, len(residue)-1)
        strSeq += residue[index]

    sequence = Seq(strSeq, IUPAC.IUPACProtein)
    seqRec = SeqRecord(sequence, id = 'randSeq' + str(seqcount), description= 'A random sequence using Amino acid residues.')
    return seqRec

def getProteinSequence(residue):
    strSeq = ""
    for i in range(0,100,1):
        index = random.randint(0, len(residue)-1)
        strSeq += residue[index]

    sequence = Seq(strSeq, IUPAC.IUPACProtein)
    return sequence

def randomProteinSeqRecord(index):
    if(index%2)==0:
        return getProteinSeqRecord(residueList1, index)
    elif(index%3)==0:
        return getProteinSeqRecord(residueList2, index)
    else:
        return getProteinSeqRecord(residueList3, index)

#information
print '--- This is python based program to generate random sequences ---'
print '--- Provide number of random sequences to generate. Default 10 ---'
print '--- Inorder to save to a file provide file path or filename ---'
print '--- If none or invalid filepath is provided then results will be displayed to console ---'
print '--- The file will be created in fasta format ---'
print

filepathProvided = False
#raw_input received the user input as string
try:
    filepath = raw_input('Enter filepath to save sequences ... ')
    filepath = filepath + '.fasta'
    #handle = open(filepath, "w")
    #handle.close()

    filepathProvided = True
except IOError:
    print 'Invalid or No File provided will print results to console'
print
ranSeqCount = 10
try:
    ranSeqCount = int(raw_input('Enter number of random sequences to generate ... '))
except ValueError:
    ranSeqCount = 10
    pass

print 'Sequence Count : '
print ranSeqCount

records = []
for i in range(0,ranSeqCount,1):
    records.append(randomProteinSeqRecord(i+1))

if(filepathProvided):
    SeqIO.write(records, filepath, "fasta")
    print 'File created at : ' + filepath

else:
    print 'Writing to console is actually not supported!  :/'

print
raw_input('Press any key to exit ...')
print

请注意：我没有安装Biopython，所以没有运行这段代码。
我在这里是想帮你，但老实说，我还有更重要的事情要做。