结果

Question

我有一个数组：

[(0, b'C', 5.8816, 6.0, 0.1184, 4.2631, 4.2631, 0.0)
 (1, b'H', 0.8495, 1.0, 0.1505, 0.951, 0.951, 0.0)
 (2, b'Br', 35.0064, 35.0, -0.0064, 1.2192, 1.2192, -0.0)
 (3, b'Cl', 17.0401, 17.0, -0.0401, 1.2405, 1.2405, -0.0)
 (4, b'F', 9.2225, 9.0, -0.2225, 1.0449, 1.0449, -0.0)]

我想从中提取单列浮点数，以便在程序中进一步使用。

当我尝试以下操作时：

QA = []
idx_IN_columns = [5]
QA = data[idx_IN_columns]

我明白了：

Traceback (most recent call last):

  File "<ipython-input-22-4e6a1b6a3f36>", line 1, in <module>
    runfile('C:/Users/Steve/Python/Testing/ReadFile_mpa_1.py', wdir='C:/Users/Steve/Python/Testing')

  File "C:\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 866, in runfile
    execfile(filename, namespace)

  File "C:\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 102, in execfile
    exec(compile(f.read(), filename, 'exec'), namespace)
    enter code here

  File "C:/Users/Steve/Python/Testing/ReadFile_mpa_1.py", line 34, in <module>
    QA = data[idx_IN_columns]

IndexError: index 5 is out of bounds for axis 1 with size 5

非常感谢协助。

提前致谢

Answer 1

data = [(0, b'C', 5.8816, 6.0, 0.1184, 4.2631, 4.2631, 0.0),
 (1, b'H', 0.8495, 1.0, 0.1505, 0.951, 0.951, 0.0),
 (2, b'Br', 35.0064, 35.0, -0.0064, 1.2192, 1.2192, -0.0),
 (3, b'Cl', 17.0401, 17.0, -0.0401, 1.2405, 1.2405, -0.0),
 (4, b'F', 9.2225, 9.0, -0.2225, 1.0449, 1.0449, -0.0)]

numbers = [n[2:] for n in data]

结果

[(5.8816, 6.0, 0.1184, 4.2631, 4.2631, 0.0), (0.8495, 1.0, 0.1505, 0.951, 0.951, 0.0), (35.0064, 35.0, -0.0064, 1.2192, 1.2192, -0.0), (17.0401, 17.0, -0.0401, 1.2405, 1.2405, -0.0), (9.2225, 9.0, -0.2225, 1.0449, 1.0449, -0.0)]

Answer 2

您的数据以及您尝试使用它的内容听起来非常适合Pandas，这是一个以表格格式处理数据的库。

>>> import pandas as pd
>>> data = [(0, b'C', 5.8816, 6.0, 0.1184, 4.2631, 4.2631, 0.0),
 (1, b'H', 0.8495, 1.0, 0.1505, 0.951, 0.951, 0.0),
 (2, b'Br', 35.0064, 35.0, -0.0064, 1.2192, 1.2192, -0.0),
 (3, b'Cl', 17.0401, 17.0, -0.0401, 1.2405, 1.2405, -0.0),
 (4, b'F', 9.2225, 9.0, -0.2225, 1.0449, 1.0449, -0.0)]
>>> df = pd.DataFrame(data)
>>> df
   0      1        2     3       4       5       6    7
0  0   b'C'   5.8816   6.0  0.1184  4.2631  4.2631  0.0
1  1   b'H'   0.8495   1.0  0.1505  0.9510  0.9510  0.0
2  2  b'Br'  35.0064  35.0 -0.0064  1.2192  1.2192 -0.0
3  3  b'Cl'  17.0401  17.0 -0.0401  1.2405  1.2405 -0.0
4  4   b'F'   9.2225   9.0 -0.2225  1.0449  1.0449 -0.0

然后，要获得第5列，只需执行df[5]。

>>> df[5]
0    4.2631
1    0.9510
2    1.2192
3    1.2405
4    1.0449
Name: 5, dtype: float64

通过使用Pandas，您还可以轻松地从（pd.read_csv()）读取并将数据（df.to_csv()）写入磁盘，例如。

从数组中提取浮点数

2 个答案:

结果