I am using Python 2.7. I want to store a variable so that I can run a script without defining the variable in that script. I think global variables are the way to do this although I am open to correction.
I have defined a global variable in file1.py
:
def init():
global tvseries
tvseries = ['Murder I Wrote','Top Gear']
In another file, file2.py
, I can call this variable:
import file1
file1.init()
print file1.tvseries[0]
If I edit the value of file1.tvseries ( file1.tvseries[0] = 'The Bill'
) in file2.py this is not stored. How can I edit the value of file1.tvseries in file2.py so that this edit is retained?
EDIT: Provide answer
Using pickle
:
import pickle
try:
tvseries = pickle.load(open("save.p","rb"))
except:
tvseries = ['Murder I Wrote','Top Gear']
print tvseries
tvseries[0] = 'The Bill'
print tvseries
pickle.dump(tvseries,open("save.p", "wb"))
Using json
:
import json
try:
tvseries = json.load(open("save.json"))
tvseries = [s.encode('utf-8') for s in tvseries]
except:
tvseries = ['Murder I Wrote','Top Gear']
print tvseries
tvseries[0] = str('The Bill')
print tvseries
json.dump(tvseries,open("save.json", "w"))
Both these files return ['Murder I Wrote','Top Gear']['The Bill','Top Gear']
when run the first time and ['The Bill','Top Gear']['The Bill','Top Gear']
when run the second time.
Try this Create a file called tvseries with these contents:
Murder I Wrote
Top Gear
file1.py :
with open("tvseries", "r") as f:
tvseries = map(str.strip, f.readlines())
def save(tvseries):
with open("tvseries", "w") as f:
f.write("\n".join(tvseries))
file2.py :
import file1
print file1.tvseries[0]
file1.tvseries.append("Dr Who")
file1.save(file1.tvseries)
I've moved the contents of your init
method out to module level since I don't see any need for it to exist. When you import file1
any code at the module level will be automatically run - eliminating the need for you to manually run file1.init()
. I've also changed the code to populate the contents of tvseries
by reading from a simple text file called tvseries containing a list of tv series and added a save
method in file1.py which will write the contents of it's argument to the file tvseries .
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