Pandas Series property: dt.is_month_start

Series.dt.is_month_start property

The is_month_start property is used to check whether a given date is the first day of the month or not.

Syntax:

Series.dt.is_month_start

Returns: Series or array
For Series, returns a Series with boolean values.
For DatetimeIndex, returns a boolean array.

Example:

Python-Pandas Code:

import numpy as np
import pandas as pd
s = pd.Series(pd.date_range("2019-02-27", periods=3))
s

Output:

0   2019-02-27
1   2019-02-28
2   2019-03-01
dtype: datetime64[ns]

Python-Pandas Code:

import numpy as np
import pandas as pd
s = pd.Series(pd.date_range("2019-02-27", periods=3))
s.dt.is_month_start

Output:

0    False
1    False
2     True
dtype: bool

Python-Pandas Code:

import numpy as np
import pandas as pd
s = pd.Series(pd.date_range("2019-02-27", periods=3))
s.dt.is_month_end

Output:

0    False
1     True
2    False
dtype: bool

Python-Pandas Code:

import numpy as np
import pandas as pd
idx = pd.date_range("2019-02-27", periods=3)
idx.is_month_start

Output:

array([False, False,  True])

Python-Pandas Code:

import numpy as np
import pandas as pd
idx = pd.date_range("2019-02-27", periods=3)
idx.is_month_end

Output:

array([False,  True, False])

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