将字典值强制转换为浮点数

Question

我是python的新手。我有一个问题，我卡住了。信息被保存在许多字典中。变量pos是文件中的一个浮点数，但是python会将其作为一个字符串读取。我想这就是为什么当compare_positions函数被调用时，我收到此错误信息：

Traceback (most recent call last): 
File "anotherPythontry.py", line 167, in <module> 
    iterate_thru(Genes,c,maxp,p) 
File "anotherPythontry.py", line 133, in iterate_thru 
    compare_positions(test_position,maxp,sn,g,p,c) 
File "anotherPythontry.py", line 103, in compare_positions 
    elif (testpos > maxpos and testpos <= maxpos+1): 
TypeError: unsupported operand type(s) for +: 'NoneType' and 'int' 

我试图使pos，testpos，maxpos浮动，但后来我得到TypeError: float() argument must be a string or a number。我不确定问题是什么。

下面是代码：

def hasher(): 
     return collections.defaultdict(hasher) 

Positions = hasher() 
LODs = hasher() 
whole_line = hasher() 
InCommon = hasher() 

def save_info(line): 
    lod = line[7] 
    chr = line[2] 
    pos = line[3] #is a float in the file. Is read as a string though 
    snp = line[1] 
    item = line[10] 
    together = '\t'.join(line) 
    whole_line[item][snp]=together 
    Positions[item][chr][snp]= pos 
    LODs[item][chr][snp]=lod 
    return snp, item 

with open(sys.argv[3],"r") as geneFile: 
    gsnp_list = list() 
    Genes = [] 
    for line in geneFile: 
      line = line.strip().split("\t") 
      type1 = line[0] 
      if "SNP_id" or "Minimum" not in line: 
        if type1 == match: 
          snp,item = save_info(line) 
          gsnp_list.append(snp) 
          if item not in Genes: 
            Genes.append(item) 
# A similar block of code is for another file with phenotypes 

def compare_positions(testpos,maxsnp,gs,gene,p,c): 
    maxpos = Positions[p][c].get(maxsnp) 
    if testpos == maxpos: 
      InCommon[p][c][maxsnp][gene].append(gs) 
    elif (testpos > maxpos and testpos <= maxpos+1): 
      InCommon[p][c][maxsnp][gene].append(gs) 
    elif (testpos < maxpos and testpos >= maxpos-1): 
      InCommon[p][c][maxsnp][gene].append(gs) 

def iterate_thru(Genelist,c,maxp,p): 
    for g in Genelist: 
      for sn in Positions[g][c].keys(): 
        test_position = Positions[g][c].get(sn) 
        compare_positions(test_position,maxp,sn,g,p,c) 

for g in Genes: 
    for c in Positions[g].keys(): 
      chr_SNPlist =() 
      chr_SNPlist = [snp for snp in gsnp_list if snp == Positions[g][c].keys()] 
      maxp = get_max(chr_SNPlist,g,c) 
      iterate_thru(Phenos,c,maxp,g) 

在此先感谢。

Answer 1

的问题是在这条线：

test_position = Positions[g][c].get(sn) 

给定请求是不是在字典，返回None作为不能相比的整数结果。然后将该值传递给compare_positions方法，在该方法中进行导致错误的比较。

根据您的应用程序，您可以尝试的默认值，如零：

test_position = Positions[g][c].get(sn, 0)