Pandas-5.基本操作

import pandas as pd
import numpy as np
s = pd.Series(np.random.randn(4))

print(s.axes)
# [RangeIndex(start=0, stop=4, step=1)]
# 这是[0, 5)的紧凑格式即[0,1,2,3,4]

print(s.empty)
# False

print(s.dtype)
# float64

print(s.ndim)
# 1

print(s.size)
# 4

s.values
# array([ 0.86667361, -1.05757677, -0.26174514, -0.49398881])

print(s.head(2))
# 0    0.866674
# 1   -1.057577
# dtype: float64

print(s.tail(2))
# 2   -0.261745
# 3   -0.493989
# dtype: float64

#Create a Dictionary of series
d = {'Name':pd.Series(['Tom','James','Ricky','Vin','Steve','Minsu','Jack']),
   'Age':pd.Series([25,26,25,23,30,29,23]),
   'Rating':pd.Series([4.23,3.24,3.98,2.56,3.20,4.6,3.8])}
#Create a DataFrame
df = pd.DataFrame(d)

print(df.T)
#            0      1      2     3      4      5     6
# Name     Tom  James  Ricky   Vin  Steve  Minsu  Jack
# Age       25     26     25    23     30     29    23
# Rating  4.23   3.24   3.98  2.56    3.2    4.6   3.8

print(df.axes)
# [RangeIndex(start=0, stop=7, step=1), Index(['Name', 'Age', 'Rating'], dtype='object')]

print(df.dtypes)
# Name       object
# Age         int64
# Rating    float64
# dtype: object

print(df.empty)
# False

print(df.ndim)
# 2

print(df.shape)
# (7, 3)

print(df.size)
# 21

print(df.values)
'''
[['Tom' 25 4.23]
 ['James' 26 3.24]
 ['Ricky' 25 3.98]
 ['Vin' 23 2.56]
 ['Steve' 30 3.2]
 ['Minsu' 29 4.6]
 ['Jack' 23 3.8]]
'''

print(df.head(2))
'''
    Name  Age  Rating
0    Tom   25    4.23
1  James   26    3.24
'''

print(df.tail(2))
'''
    Name  Age  Rating
5  Minsu   29     4.6
6   Jack   23     3.8
'''