python处理多行字符串将第一行进行修改

Question

以源代码从网站 KEGG-API获取了所需要的文本，其格式如下：

[字符串1]:

b'>hsa:10056 K01890 phenylalanyl-tRNA synthetase beta chain [EC:6.1.1.20] | (RefSeq) FARSB, FARSLB, FRSB, HSPC173, NEDBLLA, PheHB, PheRS; phenylalanyl-tRNA synthetase subunit beta (A)\nMPTVSVKRDLLFQALGRTYTDEEFDELCFEFGLELDEITSEKEIISKEQGNVKAAGASDV\nVLYKIDVPANRYDLLCLEGLVRGLQVFKERIKAPVYKRVMPDGKIQKLIITEETAKIRPF\nAVAAVLRNIKFTKDRYDSFIELQEKLHQNICRKRALVAIGTHDLDTLSGPFTYTAKRPSD\nIKFKPLNKTKEYTACELMNIYKTDNHLKHYLHIIENKPLYPVIYDSNGVVLSMPPIINGD\nHSRITVNTRNIFIECTGTDFTKAKIVLDIIVTMFSEYCENQFTVEAAEVVFPNGKSHTFP\nELAYRKEMVRADLINKKVGIRETPENLAKLLTRMYLKSEVIGDGNQIEIEIPPTRADIIH\nACDIVEDAAIAYGYNNIQMTLPKTYTIANQFPLNKLTELLRHDMAAAGFTEALTFALCSQ\nEDIADKLGVDISATKAVHISNPKTAEFQVARTTLLPGLLKTIAANRKMPLPLKLFEISDI\nVIKDSNTDVGAKNYRHLCAVYYNKNPGFEIIHGLLDRIMQLLDVPPGEDKGGYVIKASEG\nPAFFPGRCAEIFARGQSVGKLGVLHPDVITKFELTMPCSSLEINVGPFL\n'

处理成utf-8格式后：
[字符串2]：

>hsa:10056 K01890 phenylalanyl-tRNA synthetase beta chain [EC:6.1.1.20] | (RefSeq) FARSB, FARSLB, FRSB, HSPC173, NEDBLLA, PheHB, PheRS; phenylalanyl-tRNA synthetase subunit beta (A)
MPTVSVKRDLLFQALGRTYTDEEFDELCFEFGLELDEITSEKEIISKEQGNVKAAGASDV
VLYKIDVPANRYDLLCLEGLVRGLQVFKERIKAPVYKRVMPDGKIQKLIITEETAKIRPF
AVAAVLRNIKFTKDRYDSFIELQEKLHQNICRKRALVAIGTHDLDTLSGPFTYTAKRPSD
IKFKPLNKTKEYTACELMNIYKTDNHLKHYLHIIENKPLYPVIYDSNGVVLSMPPIINGD
HSRITVNTRNIFIECTGTDFTKAKIVLDIIVTMFSEYCENQFTVEAAEVVFPNGKSHTFP
ELAYRKEMVRADLINKKVGIRETPENLAKLLTRMYLKSEVIGDGNQIEIEIPPTRADIIH
ACDIVEDAAIAYGYNNIQMTLPKTYTIANQFPLNKLTELLRHDMAAAGFTEALTFALCSQ
EDIADKLGVDISATKAVHISNPKTAEFQVARTTLLPGLLKTIAANRKMPLPLKLFEISDI
VIKDSNTDVGAKNYRHLCAVYYNKNPGFEIIHGLLDRIMQLLDVPPGEDKGGYVIKASEG
PAFFPGRCAEIFARGQSVGKLGVLHPDVITKFELTMPCSSLEINVGPFL

现在我的目标是将第一行空格后的数据删除，其余不修改，完成如下：
[字符串3]：

>hsa:10056
MPTVSVKRDLLFQALGRTYTDEEFDELCFEFGLELDEITSEKEIISKEQGNVKAAGASDV
VLYKIDVPANRYDLLCLEGLVRGLQVFKERIKAPVYKRVMPDGKIQKLIITEETAKIRPF
AVAAVLRNIKFTKDRYDSFIELQEKLHQNICRKRALVAIGTHDLDTLSGPFTYTAKRPSD
IKFKPLNKTKEYTACELMNIYKTDNHLKHYLHIIENKPLYPVIYDSNGVVLSMPPIINGD
HSRITVNTRNIFIECTGTDFTKAKIVLDIIVTMFSEYCENQFTVEAAEVVFPNGKSHTFP
ELAYRKEMVRADLINKKVGIRETPENLAKLLTRMYLKSEVIGDGNQIEIEIPPTRADIIH
ACDIVEDAAIAYGYNNIQMTLPKTYTIANQFPLNKLTELLRHDMAAAGFTEALTFALCSQ
EDIADKLGVDISATKAVHISNPKTAEFQVARTTLLPGLLKTIAANRKMPLPLKLFEISDI
VIKDSNTDVGAKNYRHLCAVYYNKNPGFEIIHGLLDRIMQLLDVPPGEDKGGYVIKASEG
PAFFPGRCAEIFARGQSVGKLGVLHPDVITKFELTMPCSSLEINVGPFL

现在我的问题是：

如何获取文本后，不保存为为文件，直接对多行字符串进行处理，然后再保存为文件？
因为将获取的文本写入文件，然后再去处理这个文件感觉多此一举。

这是获取文本的代码：

def getHtml(url): #获取网页源代码
    request = urllib.request.Request(url)
    response = urllib.request.urlopen(request)
    return response.read().decode('utf-8')

url1 = "http://rest.kegg.jp/get/hsa:10056/aaseq"
text = getHtml(url1)

其中获取的‘text’内容如上[字符串2]所示
我知道可以使用split切除第一行：

>>>str1 = 'hsa:10056 K01890 phenylalanyl-tRNA synthetase beta chain [EC:6.1.1.20] | (RefSeq) FARSB, FARSLB, FRSB, HSPC173, NEDBLLA, PheHB, PheRS; phenylalanyl-tRNA synthetase subunit beta (A)'
>>>str2 = str1.split(' ')[:1]
>>>print(str2)
['hsa:10056']

但现在问题是，'text'是个多行字符串，我只要处理它的第一行，不知道如何解决？

Answer 1

不知道是不是你想要的

Answer 2

你知道换行符是\n的话，应该就知道怎么处理了吧。 str1.split("\n")[0].split(" ")[:1]