13-numpy笔记-莫烦pandas-1

import pandas as pd
import numpy as np

s = pd.Series([1,3,6,np.nan, 44,1])

print(s)

dates = pd.date_range(‘20160101‘, periods=6)
print(dates)

# index 是行的key; 默认就是数字
df = pd.DataFrame(np.random.randn(6,4), index=dates, columns=[‘a‘,‘b‘,‘c‘,‘d‘])
print(df)

df1 = pd.DataFrame(np.arange(12).reshape((3,4)))
print(df1)

df2 = pd.DataFrame({‘A‘:1.,
‘B‘:pd.Timestamp(‘20130102‘),
‘C‘:pd.Series(1,index=list(range(4)), dtype = ‘float32‘),
‘D‘:np.array([3]*4,dtype=‘int32‘),
‘E‘:pd.Categorical(["test","train","test","train"]),
‘F‘:‘foo‘})
print(df2)
print(df2.dtypes)
print(df2.index)
print(df2.columns)
print(df2.values)

#只会计算数字串
print(df2.describe())

print(df2.T)

# 对 ABCD排序
print(df2.sort_index(axis=1, ascending=False))
# 对123排序
print(df2.sort_index(axis=0, ascending=False))

print(df2.sort_values(by=‘E‘))