CODEWITHSUNDEEP
pythonpython-3.x
Shanoo
Shanoo

Reputation: 1255

Looping over list in python and appending the result in a list

I have a code like below,

from io import StringIO
a = """ab: 01dvfgf
cd: 01fgvr windows
ab: 02hjuy linux
cd: 01erttt windows
lm: 02hjkkk"""
s = StringIO(a)
a_01 = []
a_02 =[]
zone = ['01', '02']
for elements in zone:
    for line in s:
        if line[4:6] == '01':
            a_01.append(line) 
        elif line[4:6] == '02':
            a_02.append(line)

print('a_01', *a_01, sep = "\n")
print('a_02', *a_02, sep = "\n")

In this code can I replace below 4 lines into two so that I don't have to write it again and again for different zones

if line[4:6] == '01':
    a_01.append(line) 
elif line[4:6] == '02':
    a_02.append(line)

something like:

if line[4:6] == elements:
    "a_" + elements.append(line)

Upvotes: 1

Views: 60

Answers (2)

CypherX
CypherX

Reputation: 7353

Use a dict to store the values. 

from io import StringIO
a = """ab: 01dvfgf
cd: 01fgvr windows
ab: 02hjuy linux
cd: 01erttt windows
lm: 02hjkkk"""
s = StringIO(a)

zone_dict = {'01': list(), '02': list()}
for line in s:
    #print(line)
    for key in zone_dict.keys():
        #print(key)
        if line[4:6] == key:
            zone_dict[key].append(line)
zone_dict

Output: 

{'01': ['ab: 01dvfgf\n', 'cd: 01fgvr windows\n', 'cd: 01erttt windows\n'],
 '02': ['ab: 02hjuy linux\n', 'lm: 02hjkkk']}

Upvotes: 0

Marat
Marat

Reputation: 15738

from collections import defaultdict
...
s = StringIO(a)
zones = defaultdict(list)
for line in s:
    zones[line[4:6]].append(line)

for zone, lines in zones.items():  # can be iterated just as a regular dict
    print(zone, *lines, sep="\n")

Upvotes: 3

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