I am new to python. I want my script to print everything but the last line. I tried a [:-1] but I cant get it work. I know the code below isnt perfect as it is one of my first but it does everything I need it to do expect ... I dont want it to print the very last line of the string. Please help
import requests
html = requests.get("")
html_str = html.content
Html_file= open("fb_remodel.csv",'a')
html_str = html_str.replace('},', '},\n')
html_str = html_str.replace(':"', ',')
html_str = html_str.replace('"', '')
html_str = html_str.replace('T', ' ')
html_str = html_str.replace('+', ',')
html_str = html_str.replace('_', ',')
Html_file.write(html_str[:-1])
Html_file.close()
html_str is a string, not a list.
You can do something like this:
txt='''\
Line 1
line 2
line 3
line 4
last line'''
print txt.rpartition('\n')[0]
Or
print txt.rsplit('\n',1)[0]
The different between rpartition and rsplit can been seen in the docs. I would choose between one or the other based on what I wanted to happen if the split character is not found in the target string.
BTW, You may want to write your file open this way:
with open("fb_remodel.csv",'a') as Html_file:
# blah blah
# at the end -- close is automatic.
The use of with is a very common Python idiom.
If you want a general method of dropping the last n lines, this will do it:
First create a test file:
# create a test file of 'Line X of Y' type
with open('/tmp/lines.txt', 'w') as fout:
start,stop=1,11
for i in range(start,stop):
fout.write('Line {} of {}\n'.format(i, stop-start))
Then you can use a deque are loop and do an action:
from collections import deque
with open('/tmp/lines.txt') as fin:
trim=6 # print all but the last X lines
d=deque(maxlen=trim+1)
for line in fin:
d.append(line)
if len(d)<trim+1: continue
print d.popleft().strip()
Prints:
Line 1 of 10
Line 2 of 10
Line 3 of 10
Line 4 of 10
If you print the deque d, you can see where the lines went:
>>> d
deque(['Line 5 of 10\n', 'Line 6 of 10\n', 'Line 7 of 10\n', 'Line 8 of 10\n', 'Line 9 of 10\n', 'Line 10 of 10\n'], maxlen=7)