Python: Datetime to season

问题:

I want to convert a date time series to season, for example for months 3, 4, 5 I want to replace them with 2 (spring); for months 6, 7, 8 I want to replace them with 3 (summer) etc.

So, I have this series

id 1       2011-08-20 2       2011-08-23 3       2011-08-27 4       2011-09-01 5       2011-09-05 6       2011-09-06 7       2011-09-08 8       2011-09-09 Name: timestamp, dtype: datetime64[ns] 

and this is the code I have been trying to use, but to no avail.

# Get seasons spring = range(3, 5) summer = range(6, 8) fall = range(9, 11) # winter = everything else  month = temp2.dt.month season=[]  for _ in range(len(month)):     if any(x == spring for x in month):        season.append(2) # spring      elif any(x == summer for x in month):         season.append(3) # summer     elif any(x == fall for x in month):         season.append(4) # fall     else:         season.append(1) # winter 

and

for _ in range(len(month)):     if month[_] == 3 or month[_] == 4 or month[_] == 5:         season.append(2) # spring      elif month[_] == 6 or month[_] == 7 or month[_] == 8:         season.append(3) # summer     elif month[_] == 9 or month[_] == 10 or month[_] == 11:         season.append(4) # fall     else:         season.append(1) # winter 

Neither solution works, specifically in the first implementation I receive an error:

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

While in the second is a large list with errors. Any ideas please? Thanks

回答1:

You can use a simple mathematical formula to compress a month to a season, e.g.:

>>> [(month%12 + 3)//3 for month in range(1, 13)] [1, 1, 2, 2, 2, 3, 3, 3, 4, 4, 4, 1] 

So for your use-case:

>>> temp2.apply(lambda dt: (dt.month%12 + 3)//3) 1    3 2    3 3    3 4    4 5    4 6    4 7    4 8    4 Name: id, dtype: int64 

Alternatively using vector operations (credit @DSM):

>>> (temp2.dt.month%12 + 3)//3 1    3 2    3 3    3 4    4 5    4 6    4 7    4 8    4 Name: id, dtype: int64 

回答2:

I think this would work.

while True: date=int(input("Date?")) season="" if date<4:     season=1 elif date<7:     season=2 elif date<10:     season=3 elif date<13:     season=4 else:     print("This would not work.") print(season) 

文章来源: Python: Datetime to season