python - How do I save results of a "for" loop into a single variable?

8
votes

I have a for loop:

for x in range(1,13):
   print ("This was the average temperature in month number " + str(x) + " in Boston, 2014: ", Boston_monthly_temp(x))

This prints out the average monthly temperatures in Boston in 2014, such as:

This was the average temperature in month number 1 in Boston, 2014:  26.787096774193547

all the way up until Month Number 12 (December):

This was the average temperature in month number 12 in Boston, 2014:  38.42580645161291.

All in all, this for loop produces 12 lines.

However, I can't figure out how to store the results of this "for" loop into a single variable, like (output_number_one).

I'm trying to store the results into a single variable, so I can dump / write the variable (and its contents) into a pickle file, called:

output.pkl
2
pythonpersistencepickle
Since 'saving to a variable', you can ditch the print (because it is used for a side-effect and not value generation) in which case a List Comprehension would be an idiomatic approach (the link also shows how to explicitly build a list). - user2864740

2 Answers

9
votes

Try this

result = []
for x in range(1,13):
    result.append((x, Boston_monthly_temp(x)))

Now result contains the x and avg

for x, avg in result:
    print ("This was the average temperature in month number " + str(x) + " in Boston, 2014: ", avg)

You can save it to sample.pkl by

import pickle
pickle.dump(result, open("sample.pkl","w"))

Then check by

res = pickle.load(open('sample.pkl'))
>>>for i in res:
       print i
This was the average temperature ...
This was the average temperatu ...
.....
4
votes

You could simply store the results in a dictionary, pickle that and store it:

import pickle

d = {}
for x in range(1,13):
   d[x] = Boston_monthly_temp(x)
res = pickle.dumps(d)
# write res to a file