In [31]:

    

import numpy as np
import pandas as pd

a1 = np.array([1,2,3,4,5])
a1
a1.shape
a1.ndim


    

    
Out[31]:





1

In [8]:

    

x1=np.array([9, 8, 7, 6, 5, 4, 3, 2, 1, 0])

x1[5::-2]
x1


    

    
Out[8]:





array([9, 8, 7, 6, 5, 4, 3, 2, 1, 0])

In [23]:

    

x = np.array([1, 2, 3, 4, 5])

r1=x<3
list(r1)


    

    
Out[23]:





[True, True, False, False, False]

In [26]:

    

x[x<3]


    

    
Out[26]:





array([1, 2])

In [32]:

    

pd.Series({2:'a', 1:'b', 3:'c'}, index=[3, 2])


    

    
Out[32]:





3    c
2    a
dtype: object

In [47]:

    

rng = np.random.RandomState(42)
rng.randint(1,10,5)
rng.randint(0, 10, (3, 4))


    

    
Out[47]:





array([[9, 2, 6, 7],
       [4, 3, 7, 7],
       [2, 5, 4, 1]])

In [59]:

    

A = rng.randint(10, size=(3, 4))
print(A)
print(A-A[0])


    

    




[[3 8 2 4]
 [2 6 4 8]
 [6 1 3 8]]
[[ 0  0  0  0]
 [-1 -2  2  4]
 [ 3 -7  1  4]]

In [62]:

    

df = pd.DataFrame(A, columns=list('QRST'))
df - df.iloc[0]


    

    
Out[62]:







  

    

      

      
Q
      
R
      
S
      
T
    
  
  

    

      
0
      
0
      
0
      
0
      
0
    
    

      
1
      
-1
      
-2
      
2
      
4
    
    

      
2
      
3
      
-7
      
1
      
4
    
  

In [63]:

    

df.subtract(df['R'], axis=0)


    

    
Out[63]:







  

    

      

      
Q
      
R
      
S
      
T
    
  
  

    

      
0
      
-5
      
0
      
-6
      
-4
    
    

      
1
      
-4
      
0
      
-2
      
2
    
    

      
2
      
5
      
0
      
2
      
7
    
  

In [66]:

    

df.subtract(df.iloc[0], axis=1)


    

    
Out[66]:







  

    

      

      
Q
      
R
      
S
      
T
    
  
  

    

      
0
      
0
      
0
      
0
      
0
    
    

      
1
      
-1
      
-2
      
2
      
4
    
    

      
2
      
3
      
-7
      
1
      
4