创建一个函数以允许标题行和列名称列

Question

我正在定义一个函数，它将返回列表，其中元素零是2D阵列，元素之一是标题信息，元素2是rowname。我怎样才能从文件中读取这其中

文件看起来像这样：

基因S1，S2，S3 S4 S5

100 -0.243 -0.021 -0.205 -1.283 0.411

10000 - 1.178 -0.79 0.063 -0.878 0.011

def input2DarrayData(fn): 
    # define twoDarray, headerLine and rowLabels 
    twoDarray = [] 
    # open filehandle 
    fh = open(fileName) 
    # collect header information 


    # read in the rest of the data and organize it into a list of lists 
    for line in fh: 
     # split line into columns and append to array 
     arrayCols = line.strip().split('\t') 
     # collect rowname information 

     **what goes here?** 


     # convenient float conversion for each element in the list using the 
     # map function. note that this assumes each element is a number and can 
     # be cast as a float. see floatizeData(), which gives the explicit 
     # example of how the map function works conceptually. 
     twoDarray.append(map(float, arrayCols)) 
    # return data 
    return twoDarray 

我不断收到一个错误说，它不能转换为一个浮动的第一个字的文件（基因），因为它是一个字符串。所以，我的问题是搞清楚如何在阅读只是一线

Answer 1

def input2DarrayData(fn): 
    # define twoDarray, headerLine and rowLabels 
    twoDarray = [] 
    headerLine = None 
    rowLabels = [] 
    # open filehandle 
    fh = open(fn) 

    headerLine = fh.readline() 
    headerLine = headerLine.strip().split('\t') 

    for line in fh: 
     arrayCols = line.strip().split('\t') 
     rowLabels.append(arrayCols[0]) 

     twoDarray.append(map(float, arrayCols[1:])) 
    # return data 
    return [twoDarray, headerLine, rowLabels] 

如果这对你的工作，请阅读PEP-8和重构变量和函数名。另外不要忘记关闭文件。即关闭它最好使用with：

def input2DarrayData(fn): 
    "" 
    twoDarray = [] 
    rowLabels = [] 
    # 
    with open(fn) as fh: 
     headerLine = fh.readline() 
     headerLine = headerLine.strip().split('\t') 
     for line in fh: 
      arrayCols = line.strip().split('\t') 
      rowLabels.append(arrayCols[0]) 
      twoDarray.append(map(float, arrayCols[1:])) 
    # 
    return [twoDarray, headerLine, rowLabels] 

Answer 2

要处理的标题行（第一行的文件中）与.readline()消耗它明确地遍历其余的行前：

fh = open(fileName) 
headers = fh.readline().strip().split('\t') 
for line in fh: 
    arrayCols = line.strip().split('\t') 
    ## etc... 

我不确定你想从文件中获得什么数据结构;您似乎暗示了您需要包含标题的每行的列表。重复这样的标题并没有多大意义。

假设一个相当微不足道的文件结构具有标题行，并且每行柱的侧向承载力固定数，下面是一个发生器，产生用头作为键，和列的值作为值每行的字典：

def process_file(filepath): 
    ## open the file 
    with open('my_file') as src: 
     ## read the first line as headers 
     headers = src.readline().strip().split('\t') 
     for line in src: 
      ## Split the line 
      line = line.strip().split('\t') 
      ## Coerce each value to a float 
      line = [float(col) for col in line] 
      ## Create a dictionary using headers and cols 
      line_dict = dict(zip(headers, line)) 
      ## Yield it 
      yield line_dict 

>>> for row in process_file('path/to/myfile'): 
...  print row 
>>> 
>>> {'genes':100.00, 'S1':-0.243, 'S2':-0.021, 'S3':-0.205, 'S4': -1.283, 'S5': 0.411} 
>>> {'genes':10000.00, 'S1':-1.178, 'S2':-0.79, 'S3':0.063, 'S4': -0.878, 'S5': 0.011}