Get first element of Series without knowing the index [duplicate]
Is that any way that I can get first element of Seires without have information on index.
For example,We have a Series
import pandas as pd
key='MCS096'
SUBJECTS=pd.DataFrame({'ID':Series([146],index=[145]),\
'study':Series(['MCS'],index=[145]),\
'center':Series(['Mag'],index=[145]),\
'initials':Series(['MCS096'],index=[145])
})
prints out SUBJECTS:
print (SUBJECTS[SUBJECTS.initials==key]['ID'])
145 146
Name: ID, dtype: int64
How can I get the value here 146 without using index 145?
Thank you very much
Solution 1:
Use iloc to access by position (rather than label):
In [11]: df = pd.DataFrame([[1, 2], [3, 4]], ['a', 'b'], ['A', 'B'])
In [12]: df
Out[12]:
A B
a 1 2
b 3 4
In [13]: df.iloc[0] # first row in a DataFrame
Out[13]:
A 1
B 2
Name: a, dtype: int64
In [14]: df['A'].iloc[0] # first item in a Series (Column)
Out[14]: 1