Question

这是我的代码。如果我打印变量，它可以正常工作，但如果我返回它们并尝试在其他地方打印它们，则只打印最后一个元素。

def train_data(fname):

    #load csv training files
    with open (fname) as train:
        reader = csv.DictReader(train, delimiter='\t')
        for row in reader:
            peptide=[row['peptide']]
            allele=[row['allele']]
            score=[row['score']]
            #print(peptide, score, allele)
    return [peptide, allele, score]

这是我的csv文件：

peptide score   allele  
AAAGAEAGKATTEEQ 0.190842    DRB1_0101
AAAGAEAGKATTEEQ 0.006301    DRB1_0301
AAAGAEAGKATTEEQ 0.066851    DRB1_0401
AAAGAEAGKATTEEQ 0.006344    DRB1_0405
AAAGAEAGKATTEEQ 0.035130    DRB1_0701
AAAGAEAGKATTEEQ 0.006288    DRB1_0802
AAAGAEAGKATTEEQ 0.176268    DRB1_0901
AAAGAEAGKATTEEQ 0.042555    DRB1_1101
AAAGAEAGKATTEEQ 0.114855    DRB1_1302
AAAGAEAGKATTEEQ 0.006377    DRB1_1501
AAAGAEAGKATTEEQ 0.006296    DRB3_0101
AAAGAEAGKATTEEQ 0.006313    DRB4_0101
AAAGAEAGKATTEEQ 0.070413    DRB5_0101

我试着像这样打印：

if __name__=='__main__':
   p, a, s = train_data('sample.txt')
   print(s)

Answer 1

你只回归一件事。尝试将事物放入列表并返回列表：

def train_data(fname):
    peptides = []
    alleles = []
    scores = []

    #load csv training files
    with open (fname) as train:
        reader = csv.DictReader(train, delimiter='\t')
        for row in reader:
            peptides.append(row['peptide'])
            alleles.append(row['allele'])
            scores.append(row['score'])

    return peptides, alleles, scores

修改

根据您在__main__中的使用情况，我修改了我的代码以返回三个不同的列表。

Answer 2

您必须在With范围之外显示肽，等位基因，得分，否则您将始终获得[None,None,None]数组：

 def train_data(fname):

    #load csv training files
    peptide= []
    allele= []
    score = []
    with open (fname) as train:
        reader = csv.DictReader(train, delimiter='\t')
        for row in reader:
            peptide.append(row['peptide'])
            allele.append(row['allele'])
            score.append(row['score'])

    return [peptide, allele, score]

我只是猜测你不想[row['allele']]声明。

现在可以了！

Answer 3

打印变量 s 只会打印得分变量。

尝试：

print(p, a, s)

如果您希望输出看起来像上面的csv文件：

print(zip(p, a, s))

使用csv阅读器返回列表

3 个答案: