[python] Get month name from number

How can I get the month name from the month number?

For instance, if I have 3, I want to return march

date.tm_month()

How to get the string march?

import datetime

monthinteger = 4

month = datetime.date(1900, monthinteger, 1).strftime('%B')

print month

April

I created my own function converting numbers to their corresponding month.

def month_name (number):
    if number == 1:
        return "January"
    elif number == 2:
        return "February"
    elif number == 3:
        return "March"
    elif number == 4:
        return "April"
    elif number == 5:
        return "May"
    elif number == 6:
        return "June"
    elif number == 7:
        return "July"
    elif number == 8:
        return "August"
    elif number == 9:
        return "September"
    elif number == 10:
        return "October"
    elif number == 11:
        return "November"
    elif number == 12:
        return "December"

Then I can call the function. For example:

print (month_name (12))

Outputs:

>>> December

This is not so helpful if you need to just know the month name for a given number (1 - 12), as the current day doesn't matter.

calendar.month_name[i]

or

calendar.month_abbr[i]

are more useful here.

Here is an example:

import calendar

for month_idx in range(1, 13):
    print (calendar.month_name[month_idx])
    print (calendar.month_abbr[month_idx])
    print ("")

Sample output:

January
Jan

February
Feb

March
Mar

...

To print all months at once:

 import datetime

 monthint = list(range(1,13))

 for X in monthint:
     month = datetime.date(1900, X , 1).strftime('%B')
     print(month)

import datetime
mydate = datetime.datetime.now()
mydate.strftime("%B") # 'December'
mydate.strftime("%b") # 'dec'

Some good answers already make use of calendar but the effect of setting the locale hasn't been mentioned yet.

Calendar set month names according to the current locale, for exemple in French:

import locale
import calendar

locale.setlocale(locale.LC_ALL, 'fr_FR')

assert calendar.month_name[1] == 'janvier'
assert calendar.month_abbr[1] == 'jan'

If you plan on using setlocale in your code, make sure to read the tips and caveats and extension writer sections from the documentation. The example shown here is not representative of how it should be used. In particular, from these two sections:

It is generally a bad idea to call setlocale() in some library routine, since as a side effect it affects the entire program […]

Extension modules should never call setlocale() […]

For arbitaray range of month numbers

month_integer=range(0,100)
map(lambda x: calendar.month_name[x%12+start],month_integer)

will yield correct list. Adjust start-parameter from where January begins in the month-integer list.

I'll offer this in case (like me) you have a column of month numbers in a dataframe:

df['monthName'] = df['monthNumer'].apply(lambda x: calendar.month_name[x])

import datetime
mydate = datetime.datetime.now()
mydate.strftime("%B")

Returns: December

Some more info on the Python doc website

[EDIT : great comment from @GiriB] You can also use %b which returns the short notation for month name.

mydate.strftime("%b")

For the example above, it would return Dec.

8.1. datetime — Basic date and time types — Python 2.7.17 documentation https://docs.python.org/2/library/datetime.html#strftime-strptime-behavior

A list of all the strftime arguments. Names of months and nice stuff like formatting left zero fill. Read the full page for stuff like rules for "naive" arguments. Here is the list in brief: %a Sun, Mon, …, Sat

%A Sunday, Monday, …, Saturday

%w Weekday as number, where 0 is Sunday

%d Day of the month 01, 02, …, 31

%b Jan, Feb, …, Dec

%B January, February, …, December

%m Month number as a zero-padded 01, 02, …, 12

%y 2 digit year zero-padded 00, 01, …, 99

%Y 4 digit Year 1970, 1988, 2001, 2013

%H Hour (24-hour clock) zero-padded 00, 01, …, 23

%I Hour (12-hour clock) zero-padded 01, 02, …, 12

%p AM or PM.

%M Minute zero-padded 00, 01, …, 59

%S Second zero-padded 00, 01, …, 59

%f Microsecond zero-padded 000000, 000001, …, 999999

%z UTC offset in the form +HHMM or -HHMM +0000, -0400, +1030

%Z Time zone name UTC, EST, CST

%j Day of the year zero-padded 001, 002, …, 366

%U Week number of the year zero padded, Days before the first Sunday are week 0

%W Week number of the year (Monday as first day)

%c Locale’s date and time representation. Tue Aug 16 21:30:00 1988

%x Locale’s date representation. 08/16/1988 (en_US)

%X Locale’s time representation. 21:30:00

%% literal '%' character.

This Is What I Would Do:

from datetime import *

months = ["Unknown",
          "January",
          "Febuary",
          "March",
          "April",
          "May",
          "June",
          "July",
          "August",
          "September",
          "October",
          "November",
          "December"]

now = (datetime.now())
year = (now.year)
month = (months[now.month])
print(month)

It Outputs:

>>> September

(This Was The Real Date When I Wrote This)