python create a column with day and month together-CodePudding

Hi I have a dateframe of this type:

    year  month day     Date
0   2015    5   20      2015-05-20
1   2016    6   21      2016-06-21
2   2017    7   22      2017-07-22
3   2018    8   23      2018-08-23
4   2019    9   24      2019-09-24

I have created the columns "year" "month" and "day" in this way:

df["day"]  = pd.to_datetime(df["Date"]).dt.day
df["month"] = pd.to_datetime(df["Date"]).dt.month
df["year"] = pd.to_datetime(df["Date"]).dt.year

Now I want to create a 5th column with month and day together and turn them into a string

I have tried:

df["daymonth"] = str(df["day"])   " "   str(df["month"])

but it seems that I obtain a matrix, have you any suggestions?

CodePudding user response：

If one (or both) of the columns are not string typed, you should convert it (them) first:

df["daymonth"] = df["day"].astype(str)   " "   df["month"].astype(str)

CodePudding user response：

You can just do dt.strftime

df['d-m'] = df.Date.dt.strftime('%d %m')

To fix your code

df["day"].astype(str)   " "   df["month"].astype(str)

CodePudding user response：

Also you cat use something like this:

df['d-m'] = df['Date'].apply(lambda x: str(x.day)   ' '   str(x.month))