Почему я не могу преобразовать список str в список с плавающей точкой?

Question

Я начинаю писать код, но в начале он не работает.

Это мой код:

import csv
reader = csv.reader(open("QstartRefseqhg19.head"), dialect='excel-tab' )

for row in reader:
    C = row[1].split(",")[1:]
    C1 = [float(i) for i in C]

    print C1 

иЖурнал ошибок говорит:

Traceback (most recent call last):
  File "/home/geparada/workspace/SJtag/src/TagGen.py", line 8, in <module>
    C1 = [float(i) for i in C]
ValueError: empty string for float()

Я также пытался

import csv
reader = csv.reader(open("QstartRefseqhg19.head"), dialect='excel-tab' )

for row in reader:
    C = row[1].split(",")[1:]       
    C1 = map(float, C)        

    print C1

Мой входной файл выглядит так:

NM_032291   0,227,291,316,388,445,500,676,688,700,725,777,863,956,1031,1532,1660,1787,1847,1959,2115,2248,2451,2516,2681,   tttctctcagcatcttcttggtagcctgcctgtaggtgaagaagcaccagcagcatccatggcctgtcttttggcttaacacttatctcctttggctttgacagcggacggaatagacctcagcagcggcgtggtgaggacttagctgggacctggaatcgtatcctcctgtgttttttcagactccttggaaattaaggaatgcaattctgccaccatgatggaaggattgaaaaaacgtacaaggaaggcctttggaatacggaagaaagaaaaggacactgattctacaggttcaccagatagagatggaattcagcccagcccacacgaaccaccctacaatagcaaagcagagtgtgcgcgtgaaggaggaaaaaaagtttcgaagaaaagcaatggggcaccaaatggattttatgcggaaattgattgggaaagatataactcacctgagctggatgaagaaggctacagcatcagacccgaggaacccggctctaccaaaggaaagcacttttattcttcaagtgaatcggaagaagaagaagaatcacataagaaatttaatatcaagattaaaccattgcaatctaaagacattcttaagaatgctgcaactgtagatgaattgaaggcatcaataggcaacatcgcactttccccatcaccagtgaggaaaagtccgaggcgcagcccgggtgcaattaaaaggaacttatccagtgaagaagtggcaagacccaggcgttccacaccaactccagaacttataagcaaaaagcctccagatgacactacggcccttgctcctctctttggcccaccactagaatcagcttttgatgaacagaagacagaagttcttttagatcagcctgagatatggggttcaggccaaccaattaatccaagcatggagtcgccaaagttaacaaggccttttcccactggaacacctccaccactgcctccaaaaaatgtaccagctaccccaccccgaacaggatcccccttaacaattggaccaggaaatgaccagtcagccacagaggtcaaaattgaaaaactaccatccatcaatgacttggacagcatttttgggccagtattgtcccccaagtctgttgctgttaatgctgaagaaaagtgggtccatttttctgatacatccccggaacatgttactccggagttgactccaagggaaaaagtggtgtccccaccagctacaccagacaacccagctgactccccagctccaggccctctcggccccccaggtcccacaggccccccagggcctcctgggcctcctcgcaatgtactatcgccgctcaatttagaagaagtccagaagaaagtcgctgagcagaccttcattaaagatgattacttagaaacaatctcatctcctaaagattttgggttgggacaaagagcaactccacctcccccaccaccacccacctacaggactgtggtttcgtcccccggacctggctcgggccctggtccggggaccaccagtggtgcatcatcccctgctcgaccagccactcctttggttccttgcagaagtaccactccacctccacctcctccccggcctccatcccggccaaagctacctccaggaaaacctggagttggagatgtgtccagaccttttagccctcccattcattcttccagccctcctccaatagcacccttagcgcgggctgaaagcacttcttcaatatcgtcaaccaattccttgagcgcagccaccactcccacagttgagaatgaacagccttccctcgtttggtttgacagaggaaagttttatttgacttttgaaggttcttccaggggacccagccccctaaccatgggagctcaggacactctccctgttgcagcagcatttacagaaacagtcaatgcctatttcaaaggagcagacccaagcaaatgtatcgttaagattaccggagaaatggtgttgtcatttcctgctggcatcaccagacactttgccaacaacccgtccccagctgctctgacttttcgggtgataaatttcagcaggttagaacacgtcctgccaaacccccaacttctctgctgtgataatacacaaaatgatgccaataccaaggaattctgggtaaacatgccaaatttgatgactcacctaaagaaagtgtctgaacaaaaaccccaggctacatattataacgttgacatgctcaaatatcaggtgtctgcccagggcattcagtccacacctctgaacctggcagtgaattggcgatgtgagccttcaagcactgacctgcgcatagattacaaatataatacagatgcaatgacgactgctgtggccctcaacaatgtgcagttcctggtccccatcgacggaggagtcaccaagctccaggcagtgctcccaccagcagtctggaatgctgaacaacagagaatattgtggaagattcctgatatctctcagaagtcagaaaatggaggggtgggttctttgttggcaagatttcagttatctgaaggcccaagcaaaccttctccattggttgtgcagttcacaagtgaaggaagcaccctttctggctgtgacattgaacttgttggagcagggtatcgattttcactcatcaagaaaaggtttgctgcaggaaaatacttggcagataactaatgaaatcttatgcaaggatttggaggattcatataatggagaactgatgtatgagaaacagattttaattttggtttgatgaaaacaaaccaatatctgcacttgggatatatcaggtggaaagtcaatgactttcatctgtgatttccctcacacactaccatgatgaccagtcctacagtatttacttctaggtgtaatattgttaatggttttaaaatgtaattattgtatttgtaaattgtactctcattccagtaaggcagttagacacttgagttttagcattttaccattcctgaaatggatgtaatttaaactgtggtatgtaaatttaatagtagtattgttgaatggcacaatgcttacagaggtagattgcattttgtcaatatataaaatttaaatataatattgatagctgtcataaagggggtgccacatattaaagaaacttaagtggaaccagaagaaaaagaaacaaacttacttttcttcaatgcttagtatgttttactctagtgctaaataaaaactctatcttcaaatgtttagtgggttaaattgagaaactatttcagaaaaaaattctaaggttacagcatattcaaagaaaagcattagttaccactttttaaaaagcttttttttcaaactgcaaatttcataaaaatgcaaactgtgtaaacagggcctcttatttttataacttgtgtaaaaagggaaagcaattcatatttaaagtttaagtatattaaattataatcaagagtaaagaagatgttgaagtcttaactacttgcccctctctacagtttcgcaaatgtggggattgctgaataatcagtcagactaaaaccaaaattgtgattttaagatttcaagactttccgtagttgaactggttaagaatttttgcttagttactctgaatagatgatcttactcatccagtatgggggaatgatacctcacgtcttcctctttacccacaggaatcaaaacgctgagactgagaattttagggaaaaaaaagtccactgtttagatccagaaggagagttttaatcattgtttatatcatttgagaatgaaaaaataagcttcataaatgaaattctattcacattactgtgtaataaatttccttttggatgattaggattcattgtataaaactgtaaatctttgccattcttggagaagcaaaaggagagttatcaaaaatgtatgtcgtttcatcgttgcaaggtataataaaaactgtaattattcaatctggccctgccatatgaacatttagaaagacaaacttcttcgggagtctcagttgtaaaaccttccctcattaatatctgaaaatgttagtcttcctttaagtcatagaacttatttaaacataaaccaatttctattacaggttatgctattaaatagctgtaattattaagttattatttttataattagttgttaaatttcattttacacccactcaaatttaacaaagaatctttagcccctttaaattttagaattaaattaaatttttaaagttttacttctaaaatgagattgtgactggcaattgtttatagtgaaactttttaaattaatctttgtactcctctatcagtgcttgctaccaagagaatgtccaaaatgatttgttttaccatgggaaaattcttactattcaacaaactctcagttggccccctacagcagtctggtgttgaagtttctttgaacgaactaaatatactcattttatgtaaaggtatccaatttgattttgaaaccaaaatagaaaatgcaaaattctaaattccatgaaacatggaatttatgacaccaaaatcaatggagagtaagcagcagcaaactgagaattatccagcatatgaatataacaatgtgtttttaagtaatcaattcatttaaaaaattgaatattaatacaaagcatattaaaaacatgtaaatatta
NM_001080397    0,397,490,715,1443,1597,1774,1980,  atgatccccgcagccagcagcaccccgccgggagatgccctcttccccagcgtggccccacaggacttctggaggtcccaggtcacgggctactcggggtccgtgacacgacacctcagtcaccgggccaacaacttcaaacgacaccccaagaggaggaagtgcattcgtccctccccacccccgccccccaacaccccgtgcccgcttgagctggtggacttcggggacctgcacccccagaggtccttccgggagctgcttttcaacggctgcattctctttggcatcgagttcagctacgccatggagacggcgtacgtgaccccggtgctcctgcagatgggcctgcccgaccagctctacagcctggtgtggttcatcagccccatcctcggattcctactgcagcctctgttgggtgcttggagtgaccggtgtacctcaaggtttggaaggagacgccctttcattcttgtcctggctataggggcactgctgggcctctcgctcttgctgaatggccgggacattggcatcgccctggctgacgtgaccgggaaccacaagtggggcctgctgctgaccgtgtgcggtgtggtgctgatggactttagcgccgactcggcggacaaccccagccacgcctacatgatggacgtgtgcagccccgcagaccaggaccgaggcctgaacatccacgccctcctggcaggtctcggaggaggctttggatacgtggtcggcggaatccactgggataaaacgggcttcgggagggccctggggggacagctccgagtcatttacctcttcactgcggtcaccctgagcgtcaccaccgtcctgaccctggtcagcatccctgagaggccgctgcggccgccgagtgagaagcgggcagccatgaagagccccagcctcccgctgcccccgtccccacccgtcctgccagaggaaggccctggcgacagcctcccgtcgcacacggccaccaacttctccagccccatctcgccgcccagccccctcacgcccaagtacggcagcttcatcagcagggacagctccctgacgggcatcagcgagttcgcctcatcctttggcacggccaacatagacagcgtcctcattgactgcttcacgggcggccacgacagctacctggccatccctggcagcgtccccaggccgcccatcagcgtcagcttcccccgggcccccgacggcttctaccgccaggaccgtggacttctggagggcagagagggtgccctgacctccggctgtgacggggacattctgagggtgggctccttggacacctctaagccgaggtcatcagggattctgaagagacctcagaccttggccatcccggacgcagccggaggagggggtcccgaaaccagcaggagaaggaatgtgaccttcagtcagcaggtggccaatatcctgctcaacggcgtgaagtatgagagcgagctgacgggctccagcgagcgcgcggagcagcctctgtccgtggggcgcctctgctccaccatctgcaacatgcccaaggcgctacgcaccctctgcgtcaaccacttcctggggtggctctcattcgaggggatgttgctcttctacacagacttcatgggcgaggtggtgtttcagggggaccccaaggccccgcacacatcagaggcgtatcagaagtacaacagcggcgtgaccatgggctgctggggcatgtgtatctacgccttcagtgctgccttctactcagctatcctggagaagctggaggagttcctcagcgtccgcaccctctacttcatcgcctatctcgccttcggcctggggaccgggcttgccaccctctccaggaacctctacgtggtcctgtcgctctgcataacctacgggattttattttccaccctgtgcaccttgccttactcgctgctctgcgattactatcagagtaagaagtttgcagggtccagtgcggacggcacccggcggggcatgggcgtggacatctctctgctgagctgccagtacttcctggctcagattctggtctccctggtcctggggcccctgacctcggccgtgggcagtgccaacggggtgatgtacttctccagcctcgtgtccttcctgggctgcctgtactcctccctgtttgtcatttatgaaattcctcccagcgacgctgcagacgaggagcaccggcccctcctgctgaacgtctgacatcgcggagcctcgactccggacacgcgcctgcacctgggggtctggagcaggccgaccagtgaggaccaaagggccttgttggacagggggactggctgcctactggaatgtaaatatgtgataaaataataaatgacagcggcaaagccta
NM_001145277    0,182,283,388,470,579,757,  gaaacctggtcagagagtcgcaccgcttccgtccgtcggacagaggaacggtggaagtcgccggaagttcggtgggctccaggcgtcgcgatggaggagagcgggtacgagtcggtgctctgtgtcaagcctgacgtccacgtctaccgcatccctccgcgggctaccaaccgtggctacagggctgcggagtggcagctggaccagccatcatggagtggccggctgaggatcactgcaaagggacagatggcctacatcaagctggaggacaggacgtcaggggagctctttgctcaggccccggtggatcagtttcctggcacagctgtggagagtgtgacggattccagcaggtacttcgtgatccgcatcgaagatggaaatgggcgacgggcgtttattggaattggcttcggggaccgaggtgatgcctttgacttcaatgttgcattgcaggaccatttcaagtgggtgaaacagcagtgtgaatttgcaaaacaagcccagaacccagaccaaggccctaaactggacctgggcttcaaggagggccagaccatcaagctcaacatcgcaaacatgaagaagaaggaaggagcagctgggaatccccgagtccggcctgccagcacaggagggctgagcctgcttccccctcccccaggggggaaaacctccaccctgatccctccccctggggagcagttggctgtggggggatccctcgtccagccagcagttgctcccagttcagatcaacttccagccagacccagccaggcacaggctgggtccagttctgacctgagcacggtttttcctcatgtgacttctgggaaggcgctccctcatctgggccaaaggaaggaggacgaagccctcctcagctggcctgtgtttggggcatgaatctctcctctcctccttgtctggctctgttgacaaaccgggcatgtttggcagtaaattggcaccgtgtcacactgtttcctgggattcaagtatgcaaccagaacacaggagaagaaaagctccaggatccctgtccccatctgtcctcttgatgtgagagagactctgagacttcttccatcgcaatgacctgtattaaacacaagccccccaagcaaaagaagaggttgagtttgctgccaggattcagatcagcccttcccagggtctgcaggtgtcacatgatcacagttcagcgggaggctttccgtacccacactggctgtagccacttcagtccatctgccctccagaggaggggtttcttcctgatttttagcaggtttagaggctgcagcttgagctacaatcaggagggaaattggaaggattagcagcttttaaaaatgtttaaatattttgctttgctaatgtgctgatccgcactaactcatctttgcaaaaggaactgctccctcggcgtgccccagctggggcctctgaagggattcctcactgtgggcagctgccctgagcttcaggcagcagtgtttatctctggccagttgtctggtttccatgtattctaggccaggtaggcaacacagagccaaggcgggtgctggaagccagacggaacagtgttggggcaggaaggtggatgctgttgtcatggagctgtgggagttggcactctgtctgctggtggccctctcggctcacatgttcacagtgcagctcctggcagacttgggttttctctttggtggtttctaaagtgccttatctgcaaacaacttcttttctccttcaggaactgtgaatggctagaagaaggagctcagtaaactagaagtccagggttgcttggtttactggtttataagaaatctgaaagcacctctgacattccttttattaactcacctctcagttgaaagatttcttctttgaaaggtcaagaccgtgaactgaaaaaagtgttggcctttttgcgggaccagatttttaagataaaataaatatttttacttctgtcattgtatgtgaaaaaaaaaaaaa

Я стек, спасибо за ваше время !!

Answer 1

Ваша строка ввода заканчивается запятой, например:

0,182,283,388,470,579,757,

Естественно, это будет разбито на:

['0', '182', '283', '388', '470', '579', '757', '']

Последний элемент всегда будет пустой строкой''.Вы должны были бы учитывать это.Один из способов - просто проигнорировать его:

C1 = [float(i) for i in C if i]

Или вырезать последний элемент перед кастом:

C = row[1].split(",")[1:-1]   # the slice will exclude first and last elements

Answer 2

вы можете использовать try / кроме случаев преобразования в float и перехвата ValueErrors.

C = row[1].split(",")[1:] 
    for item in C:
    try:
        convert=float(item)
    except ValueError:
        print "not a number"