Python 如何仅显示前20个条目
这里的Python代码得到了我想要的输出。但是,我需要帮助将结果限制在前20行 输入示例如下所示 gi | 170079688 |参考| YP | U 001729008.1 |双功能核黄素激酶/FMN腺苷酸转移酶[大肠杆菌str.K-12 substr.DH10B] MKLIRGIHNLSQAPQEGCVLTIGNFDGHRGHRALLQEGRKNLPVMVMLFEPQPLELFATDKAPA RLTRLREKLRYLAECGVDYVLCVRFDRRFAALTAQNFISDLVKHLRVKFLAVGDDFRFGAGREGDFLLL Qkagmeygfditstqtfceggvrisstavrqaladdnlaeslghpfaisgrvghgdelgrtigfpta NVPLRRQVSPVKGVYAVEVLGLGEKPLPGVANIGTPVAGIRQEVHLLDVAMDLYGRHIQVVLRKKI Rneqrfasldelkaqiardertareffgltkpa gi | 170079689 |参考| YP | U 001729009.1 |异亮氨酸tRNA合成酶[大肠杆菌str.K-12 substr.DH10B] msdykstlpetgfpmrgdlakrepgmlarwtdddlygiirakkgkktfillhdgppyangsihighsv NKILKDIIVKSKGLSGYDSPYVPGWDCHGLPIELKVEQEYGKPGEKFTAAEFRAKCREYAATQVDGQRKD FirlGVLGDWSHPYLTMDFKTEANIIRAGKIIGNGLHKGAKPVHWCVRASALEAVEYYDKTSPSI DVAFQAVDQDALKAKFAVSNVNGPISLVIWTTPLPANRAISIAPDYALVQIDGQAVILLAKDLVES VMQRIGVTDYTILGTVKGAELELLRFTHPFMGFDVPAILGDHVTLDAGTGAVHTAPGHGPDDYVIGQKYG LetanPVGPDGTYLPGTYPTLDGVNVFK和VwallQekgallhVEKMQHSYPCWRHKTPIIFRATPQ WFVSMDQKGLAQSLKEIKGVQWIPDWGQARIESMVANRPDWCISRQRTWGVPMSLFvHKDTEELHPRTL Elmeevakrvevdgiqawdwdldakeilgdeqyvkvpdtldvwfdsgssvvdvrpefeaghaadmyl EGSDQHRGWFMSSLMISTAMKGKKKKKKKKKKKKKKKKKKGQQDVMKLKdILLWVA STDYTGEMAVSDEILKRAADSYRRIRRNTARFLANGFDPAKDMVKPEEMVVLDRWAVGCAAQEDIL Kayeaydfhevqrlmrfcvemgsfyldiikdrqytakadsvarrscqtalyhiaelvrwmapilsft Adevwgylpgerekyvftgewyeglfgladseamndafwdelkvrgevnkvieqaradkvggsleav Tlyaepelsakltalgdelrfvlltsgatvadyndaqsevlkglkvalskaegekcprcwytqd VGVAEHAEICGRCVSNVAGGEKFA gi | 170079690 | ref | YP | U 001729010.1 |脂蛋白信号肽酶[大肠杆菌str.K-12 substr.DH10B] MSQSICSTGLRWLVVLIVLIIDLGSKYLILQNFALGDTVPLFSLNLNYARNYGAFSFLADSGGWQRW FFAGAIGISISVILAVMMYRSKATQKLNIYALIGGALGNLFDRLWHGFVDMIDFYVGDFWHFATFNLA DTAICVGAALIVLEGFLPSRAKKQPython 如何仅显示前20个条目,python,python-3.x,output,Python,Python 3.x,Output,这里的Python代码得到了我想要的输出。但是,我需要帮助将结果限制在前20行 输入示例如下所示 gi | 170079688 |参考| YP | U 001729008.1 |双功能核黄素激酶/FMN腺苷酸转移酶[大肠杆菌str.K-12 substr.DH10B] MKLIRGIHNLSQAPQEGCVLTIGNFDGHRGHRALLQEGRKNLPVMVMLFEPQPLELFATDKAPA RLTRLREKLRYLAECGVDYVLCVRFDRRFAALTAQNFISDLVKHLRVKFL
在最上面,添加
c=0
。然后,改变
print("{0} length:{1} {2}".format(id, len(seq),header))
到
使用:
在最上面,添加
c=0
。然后,改变
print("{0} length:{1} {2}".format(id, len(seq),header))
到
使用:
在
a_文件上使用slicing
操作符。在a_文件上使用slicing
操作符。这会读取输入文件的前20行,但我需要打印前20行结果。实际上我以前尝试过这种方法,但它给了我一个错误打印行上的“缩进中制表符和空格的使用不一致”。这会读取输入文件的前20行,但我需要打印结果的前20行。实际上我以前尝试过这种方法,但在打印行上出现错误“缩进中制表符和空格的使用不一致”。
if c < 10:
print("{0} length:{1} {2}".format(id, len(seq),header))
c += 1
import re
id = None
header = None
seq = ''
with open('e_coli.faa') as a_file:
for line in a_file:
m = re.match(">(\S+)\s+(.+)", line.rstrip())
if m:
if id and c < 20:
print("{0} length:{1} {2}".format(id, len(seq),header))
c += 1
id, header = m.groups()
seq = ''
else:
seq += line.rstrip()
for line in a_file:
for line in a_file.readlines()[:20]: