[Python] Pandas's sort_values isin use skills __python

1. In the dataframe of pandas, we often need to select the rows of a specified condition based on a property, at which point the Isin method is particularly effective.

Import pandas as PD
DF = PD. Dataframe ([[1,2,3],[1,3,4],[2,4,3]],index = [' One ', ' two ', ' three '],columns = [' A ', ' B ', ' C '])
print DF
#        A  B  C
# One    1  2  3
# two    1  3  4
# three  2  4 3

Let's say we choose a row with a value of 1 in column A.

Mask = df[' A '].isin ([1]) #括号中必须为list
print Mask
# one       true
# two       True
# three    False
# name:a, dtype:bool
print Df[mask]
#      A  B  C
# one  1  2  3
# Two  1  3  4

The dataframe in 2.pandas how to sort by the first keyword, the second keyword, here you can use Sort_values, the old version of Sort_index.

Import pandas as PD
DF = PD. Dataframe ([[1,2,3],[2,3,4],[2,4,3],[1,3,7]],
                  index = [' One ', ' two ', ' three ', ' four '],columns = [' A ', ' B ', ' C ']]
print DF
#        A  B  C
# one    1  2  3
# two    2  3  4
# Three  2  4  3
# four   1  3  7
df.sort_values (by=[' A ', ' B '],ascending=[0,1],inplace =true)
print DF
#        A  B  C
# two    2  3  4
# three  2  4  3
# One    1  2  3
# four   1  3  7