Python 将列表元素转换为数组
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Convert list elements into array
提问by rond
I have a list tsv file which I am parsing and want to convert it into an array.
我有一个列表 tsv 文件，我正在解析它并希望将其转换为数组。
Here is the file format -
这是文件格式 -
jobname1 queue maphours reducehours
jobname2 queue maphours reducehours
code
代码
with open(file.tsv) as tsv:
line = [elem.strip().split('\t') for elem in tsv]
vals = np.asarray(line)
print vals[0]
print vals[4]
Vals currently returns the following output -
Vals 当前返回以下输出 -
['job1', 'queue', '1.0', '0.0\n']
['job2', 'queue', '1.0', '0.0\n']
I want to convert each element in a row in the entire file to an array object -
我想将整个文件中一行中的每个元素转换为一个数组对象 -
vals[0] = job1 vals[1] = queue vals[2] = 1.0 vals[3] = 0.0
How do i achieve this?
我如何实现这一目标？
采纳答案by Marcin
From what I understand you would like to create 2D array in numpy where each row of the file is a row corresponds to the created array, and column in a file is a column in the array. If so, you could do this as follows:
据我了解，您想在 numpy 中创建二维数组，其中文件的每一行都是一行对应于创建的数组，文件中的列是数组中的一列。如果是这样，您可以按如下方式执行此操作：
For example, if your data file is:
例如，如果您的数据文件是：
jobname1 queue 1 3
jobname2 queue 2 4
jobname41 queue 1 1
jobname32 queue 2 2
jobname21 queue 3 4
jobname12 queue 1 6
The following code:
以下代码：
with open(file) as tsv:
line = [elem.strip().split('\t') for elem in tsv]
vals = np.asarray(line)
will result in the following valsarray:
将导致以下vals数组：
[['jobname1' 'queue' '1' '3']
['jobname2' 'queue' '2' '4']
['jobname41' 'queue' '1' '1']
['jobname32' 'queue' '2' '2']
['jobname21' 'queue' '3' '4']
['jobname12' 'queue' '1' '6']]
The get the job names you can do:
获取您可以执行的工作名称：
print(vals[:,0])
% gives ['jobname1' 'jobname2' 'jobname41' 'jobname32' 'jobname21' 'jobname12']
Or if you want rows containing some job, you can do:
或者，如果您想要包含某些作业的行，您可以执行以下操作：
print(vals[np.apply_along_axis(lambda row: row[0] == 'jobname1', 1, vals)])
回答by rofls
Are you sure you need an array? @Marcin's answer is more complete if you want a Numpy array.
你确定你需要一个数组吗？如果你想要一个 Numpy 数组，@Marcin 的答案会更完整。
Python doesn't have an array data structure (there's a list of Python data structures here). There is a "thin wrapper around the C array". In order to use the wrapper around the C array, you have to specify a type that the array will hold (hereyou'll find a list of typecodes, at the top, and examples at the bottom):
Python没有一个数组（有Python数据结构的列表在这里）。有一个“围绕 C 数组的薄包装”。为了在 C 数组周围使用包装器，您必须指定数组将保存的类型（在这里，您将在顶部找到类型代码列表，在底部找到示例）：
If you want to use a numpy array, this should work:
如果你想使用一个 numpy 数组，这应该可以工作：
import numpy as np
myarray = np.asarray(yourList)
adopted from here.
从这里采用。
