pandas入门：整数索引

from pandas import Series, DataFrame
import numpy as np

ser = Series(np.arange(3))
print(ser)
'''
0    0
1    1
2    2
dtype: int64
'''
#print(ser[-1]) # 整数索引会报错
print(ser.loc[:1])
'''
0    0
1    1
dtype: int64
'''
ser2 = Series(np.arange(3),index=['a','b','c'])
print(ser2)
'''
a    0
b    1
c    2
dtype: int64
'''
print(ser2[-1]) # 非整数索引没有歧义，不会报错
'''
2
'''
ser3 = Series(range(3),index=[-5,1,3])
print(ser3)
'''
-5    0
 1    1
 3    2
dtype: int64
'''
#print(ser3.iget_value(2))
print(ser3.iat[2])
'''
2
'''

frame = DataFrame(np.arange(6).reshape(3,2),index=[2,0,1])
print(frame)
'''
   0  1
2  0  1
0  2  3
1  4  5
'''
#print(frame.irow(0))
print(frame.iloc[0])
'''
0    0
1    1
Name: 2, dtype: int64
'''