Find indices of rows of dates falling within datetime range-CodePudding

Using datetime and a dataframe, I want to find which rows fall within the range of dates I have specified.

Sample dataframe:

times = pd.date_range(start="2018-01-01",end="2020-02-02")
values = np.random.rand(512)

# Make df
df = pd.DataFrame({'Time' : times, 
                   'Value': values})

How do I easily select all values that fall within a certain month or range?

I feel like a good step is using:

pd.to_datetime(df['Time']).dt.to_period('M')
>>> df
0      2018-01
1      2018-02
2      2018-03

But I wouldn't know how to contine. I would like to be able to select a year/month like 2019-01 or a range 2019-01:2020-01 to find the indices in the dataframe that the input.

CodePudding user response：

I apparently did the right thing already, but had a wrong syntax.

It was quick, but just to be sure here is the answer:

np.where(pd.to_datetime(df['time']).dt.to_period('M') == '2018-01')

Then a range can be specified as well.

CodePudding user response：

With query you can also select date ranges pretty quickly:

df.query('"2019-01-01" <= Time < "2019-02-01"')