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Python looping 300 000 rows
Based on my last question comes new one.
How to loop over 300 000 rows and edit each row string one by one?
I have a list of 11-digit numbers stored in one single column in Excel, and I need to separate the digits according to this pattern: 2-2-1-3-3
.
I use the code below to loop to test the solution for only 20 rows and it's working.
Example: 00002451018
becomes 00 00 2 451 018
.
priceListTest
contains the column Column1
which has these 11 digit numbers. Somehow I need to loop all over these 300 000 rows and use the get_slices
to change the pattern for each row like from the example above and store it into the new column New Value
.
The for index, row
it's working very slowly when I have to use it for 300 000 rows. Maybe there is a better method, but I'm new to python.
Thanks in advance!
for index, row in priceListTest.iterrows():
#print(index,row)
def get_slices(n, sizes, n_digits=11):
for size in sizes:
n_digits -= size
val, n = divmod(n, 10 ** n_digits)
yield f'{val:0{size}}'
n = row['Column1']
newVar = (' '.join(get_slices(n, [2, 2, 1, 3, 3])))
priceListTest.at[index,['New Value']] = newVar
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