appending a list with using input values in a for loop

Question

I have two list, an empty list(newgr) and the other got values that has been imported from an excel sheet(gr). I'm trying to iterate through the list in a for-loop so that I can compare and change some of the values and append the values in gr that have changed with the original values into newgr. I tried this format but it wasn't working.

df = pd.read_excel("Well_Logs.xlsx", "SB16", na_values = [-999])
newgr = []
gr = df['GR'].values.tolist()

grclean = int(input('enter your clean value >')) #20 for example
grclay = int(input('enter your clay value >')) #60 for example

for i in gr:

    if i < grclean:
        i==grclean
        newgr.append(i)
    elif i > grclay:
        i==grclay
        newgr.append(i)
    else:
        newgr.append(i)

print(newgr)

I'm expecting the list to have some new values to work with, rather the same values of gr is appended to newgr.

Just for clarification, when you print newgr, you only get the values that are in gr right? — D.Sanders
– D.Sanders, Commented Apr 10, 2019 at 13:55

AKX · Accepted Answer · 2019-04-10 13:57:41Z

2

You should use

i = grclean

to assign grclean to i

instead of

i == grclean

which is a comparison.

You can also write the entire loop as a neat list comprehension:

newgr = [max(grclean, min(grclay, i)) for i in gr]

answered Apr 10, 2019 at 13:57

AKX

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3 Comments

YeBron Over a year ago

I tried this code on its own and it worked but it gave me an error when I ran it as part of my script.

YeBron Over a year ago

'<' not supported between instances of 'float' and 'NoneType'

AKX Over a year ago

Your list contains Nones then.

Christopher_Okoro · Accepted Answer · 2019-04-10 14:02:16Z

0

df = pd.read_excel("Well_Logs.xlsx", "SB16", na_values = [-999])
newgr = []
gr = df['GR'].values.tolist()

grclean = int(input('enter your clean value >')) #20 for example
grclay = int(input('enter your clay value >')) #60 for example

for i in gr:

    if i < grclean:
        newgr.append(grclean)
    elif i > grclay:
        newgr.append(grclay)
    else:
        newgr.append(i)

print(newgr)

answered Apr 10, 2019 at 14:02

Christopher_Okoro

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1 Comment

YeBron Over a year ago

Thanks. Makes sense

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