pandas系列获取'数据必须是1维'错误

Question

I'm new to pandas & numpy. I'm running a simple program

labels = ['a','b','c','d','e'] 
s = Series(randn(5),index=labels)
print(s)

getting the following error

    s = Series(randn(5),index=labels)   File "C:\Python27\lib\site-packages\pandas\core\series.py", line 243, in
__init__
    raise_cast_failure=True)   File "C:\Python27\lib\site-packages\pandas\core\series.py", line 2950, in
_sanitize_array
    raise Exception('Data must be 1-dimensional') Exception: Data must be 1-dimensional

Any idea what can be the issue? I'm trying this using eclipse, not using ipython notebook.

Answer 1

It seems you need numpy.random.rand for random floats or numpy.random.randint for random integers :

import pandas as pd
import numpy as np

np.random.seed(100)
labels = ['a','b','c','d','e'] 
s = pd.Series(np.random.randn(5),index=labels)
print(s)
a   -1.749765
b    0.342680
c    1.153036
d   -0.252436
e    0.981321
dtype: float64

---

np.random.seed(100)
labels = ['a','b','c','d','e'] 
s = pd.Series(np.random.randint(10, size=5),index=labels)
print(s)
a    8
b    8
c    3
d    7
e    7
dtype: int32

Answer 2

I suspect you have your imports wrong

If you add this to your code

from pandas import Series
from numpy.random import randn

labels = ['a','b','c','d','e'] 
s = Series(randn(5),index=labels)
print(s)

a    0.895322
b    0.949709
c   -0.502680
d   -0.511937
e   -1.550810
dtype: float64

It runs fine.

That said, and as pointed out by @jezrael, it's better practice to import the the modules rather than pollute the namespace.

Your code should look like this instead.

solution

import pandas as pd
import numpy as np

labels = ['a','b','c','d','e'] 
s = pd.Series(np.random.randn(5),index=labels)
print(s)