for loop count monthly total python

I have a data and here has some date time.

like this:

datetime
2022-01-01
2022-02-01
2022-02-01
2022-03-01
2022-03-01
2022-03-01
2022-04-01
2022-04-01
2022-04-01
2022-04-01
2022-04-01
2022-04-01
2022-04-01
2022-04-01
2022-04-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01
2022-05-01

I need to count monthly total so I do something like this

my code is:

df = pd.read_csv('example.csv')
example_per_month = []
for a in range(1,6):
    example = {}
    example[str(a)] = len(df[(df['datetime'] >= '2022-0'+str(a)+'-01')&(df['datetime'] <= '2022-0'+str(a)+'-31'))])
    example_per_month.append(example)
print(example_per_month)

And her is my output:

[{'1':1},{'2':2},{'3':3},{'4':9},{'5':14}]

But I need the total count month by month now.

expected output:

[{'1':1},{'2':3},{'3':6},{'4':15},{'5':29}]

Thanks in advance

Answer

this is not the exact solution you want but hope this will help you to find a solution

values = [{'1':10},{'2':20},{'3':30},{'4':9},{'5':14},{'6':37}]

loop = 1
total = 0
for val in values:
    total += val[str(loop)]
    val[str(loop)] = total
    print(val[str(loop)])
    loop += 1
    
print(total)