How can I determine the relationship between spam and weekdays? I am trying to check if there is a correlation between spam emails and weekdays.
My dataset looks like as follows:
  Spam? Day
0   1.0 Saturday
1   1.0 Saturday
3   0.0 Saturday
5   1.0 Saturday
7   0.0 Friday
... ... ...
346 0.0 Friday
348 1.0 Friday
361 0.0 Saturday
383 1.0 Thursday
387 1.0 Friday

where 1 means spam and 0 not spam.
I have tried as follows
corr = (numpy.corrcoef(df['Spam?'],df['Days']))

I do not know how to explain a possible relationship between these two variables and if a plot could help to better visualise data and relationship.
(started as a comment but it turned out to be longer than expected)
With a dataset like this a simple barplot could be very insightful: on the X axis the days of the week, on the Y axis the frequency, with two bars (spam/not spam using different color) for each day. A slightly more advanced version: two boxplots, one for weekdays the other for weekends. A boxplot is kind of overkill for only 5 (mon-fri) and 2 (sat-sun) values but it's easy to do and shows the big picture.
In order to test whether any difference (e.g. weekdays vs weekends) is significant I think this is a good case for a chi square test.