(while, while not) multiply conditions //python loop

Problem with a loop in Python. Below below there's a 'handwritten' code - which works and it works in a way it's supposed to work. I explain:

• new[i] is a list where each element is a time of a blink.
• df2[' time'][i] and df2[' time'][i+1] designate a time range for new[i]; if the time of new[i] is between those two df2s...[i],[i+1], then print(df2['letter'][i]) - else try with a higher index until you find the right range, then print a letter with that higher index.

Ok so it works. But when I try to write an algorithm using WHILE .. AND or WHILE NOT .. AND, (tried a few versions...) e.g.:

(this doesn't work:)

for j in range(len(new)):
    while not new[j]>df2[' time'][i] and new[j]<df2[' time'][i+1]:
        i+1
    prin开发者_运维问答t(df2['letter'][i])

, which I understand as:

• for each element in list new[], as long as this element isn't bigger than df2[' time'][i] and isn't smaller then time df2[' time'][i+1], increase iteration by one, unless you found the right match, then print df2['letter'][i].

My problem is that i is always 1, no matter what. Basically: what's wrong in my algorithm?

(this works:)

if new[0]>df2[' time'][0] and new[0]<df2[' time'][1]:
    print(df2['letter'][0])
elif new[0]>df2[' time'][1] and new[0]<df2[' time'][2]:
    print(df2['letter'][1])
if new[1]>df2[' time'][2] and new[1]<df2[' time'][3]:
    print(df2['letter'][2])
elif new[1]>df2[' time'][3] and new[1]<df2[' time'][4]:
    print(df2['letter'][3])
if new[2]>df2[' time'][4] and new[2]<df2[' time'][5]:
    print(df2['letter'][4])
elif new[2]>df2[' time'][5] and new[2]<df2[' time'][6]:
    print(df2['letter'][5])
elif new[2]>df2[' time'][6] and new[2]<df2[' time'][7]:
    print(df2['letter'][6])
elif new[2]>df2[' time'][7] and new[2]<df2[' time'][8]:
    print(df2['letter'][7])
elif new[2]>df2[' time'][8] and new[2]<df2[' time'][9]:
    print(df2['letter'][8])
elif new[2]>df2[' time'][9] and new[2]<df2[' time'][10]:
    print(df2['letter'][9])
elif new[2]>df2[' time'][10] and new[2]<df2[' time'][11]:
    print(df2['letter'][10])
elif new[2]>df2[' time'][11] and new[2]<df2[' time'][12]:
    print(df2['letter'][11])

I tried while not loop with conjunction. Increase iteration by 1 seems not working.

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You aren't actually updating i here. You need to state i=i+1