I am new to Python.
What I am trying to do is to split what I got from a txt file to select just the Aperture and the ShutterSpeed values.
This is how my data looks like (30 different values of Aperture and Shutter Speed) :
======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083601_0004_RED.TIF
Aperture : 2.2
Shutter Speed : 1/1806
======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083600_0003_NIR.TIF
Aperture : 2.2
Shutter Speed : 1/510
======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083601_0004_REG.TIF
Aperture : 2.2
Shutter Speed : 1/374
======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083600_0003_RED.TIF
Aperture : 2.2
Shutter Speed : 1/1884
I need to make my code select only the float values (2.2, and 1/1884 for example from all the data).
This is the code I am trying to do (with the help of some people here) :
filename='/home/stagiaire/Bureau/datatest.txt'
with open(filename) as f:
data = f.read()
data = data.split('\n')
Fnumber = [float(row.split(':')[0]) for row in data]
ShutterSpeed = [float(row.split(':')[1]) for row in data]
Any suggestions?
You can use slice operator(:) to filter out the text you need, something like this :
# -*- coding: utf-8 -*-
data = [
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083601_0004_RED.TIF Aperture : 2.2 Shutter Speed : 1/1806",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083600_0003_NIR.TIF Aperture : 2.2 Shutter Speed : 1/510",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083601_0004_REG.TIF Aperture : 2.2 Shutter Speed : 1/374",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083600_0003_RED.TIF Aperture : 2.2 Shutter Speed : 1/1884"
]
for node in data :
node_lst = node[node.index('Aperture : '):].split()
Fnumber = node_lst[2]
ShutterSpeed = node_lst[6]
print(Fnumber, ShutterSpeed)
Alternatively, you can do this without having to use .split() on your data :
# -*- coding: utf-8 -*-
data = [
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083601_0004_RED.TIF Aperture : 2.2 Shutter Speed : 1/1806",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083600_0003_NIR.TIF Aperture : 2.2 Shutter Speed : 1/510",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083601_0004_REG.TIF Aperture : 2.2 Shutter Speed : 1/374",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083600_0003_RED.TIF Aperture : 2.2 Shutter Speed : 1/1884"
]
for node in data :
Fnumber_txt = node[node.index('Aperture : ') + len('Aperture : '):]
Fnumber = Fnumber_txt[:Fnumber_txt.index(' ')]
ShutterSpeed = node[node.index('Shutter Speed : ') + len('Shutter Speed : '):]
print(Fnumber, ShutterSpeed)
Both of the above code snippets will produce this result :
2.2 1/1806
2.2 1/510
2.2 1/374
2.2 1/1884
Edit : As you have data at three different indexed for one entity, you can use step of slice operator to fetch it and process, something like this :
# -*- coding: utf-8 -*-
data = [
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083601_0004_RED.TIF",
"Aperture : 2.2",
"Shutter Speed : 1/1806",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083600_0003_NIR.TIF",
"Aperture : 2.2",
"Shutter Speed : 1/510",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083601_0004_REG.TIF",
"Aperture : 2.2",
"Shutter Speed : 1/374",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083600_0003_RED.TIF",
"Aperture : 2.2",
"Shutter Speed : 1/1884"
]
fns = [float(fn.split(":")[-1].strip()) for fn in data[1::3]]
sss = [ss.split(":")[-1].strip().split("/") for ss in data[2::3]]
for i, elems in enumerate(sss) :
Fnumber = fns[i]
Shutter = elems[0]
Speed = elems[1]
print(Fnumber)
print(Shutter)
print(Speed)
This will result in :
2.2
1
1806
2.2
1
510
2.2
1
374
2.2
1
1884
Alternatively, you can format your final result like this :
# -*- coding: utf-8 -*-
data = [
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083601_0004_RED.TIF",
"Aperture : 2.2",
"Shutter Speed : 1/1806",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083600_0003_NIR.TIF",
"Aperture : 2.2",
"Shutter Speed : 1/510",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083601_0004_REG.TIF",
"Aperture : 2.2",
"Shutter Speed : 1/374",
"======== /home/stagiaire/Bureau/Photos Test Luxmetes/Position 2 (au sol à l'ombre)/0033/IMG_170407_083600_0003_RED.TIF",
"Aperture : 2.2",
"Shutter Speed : 1/1884"
]
fns = [float(fn.split(":")[-1].strip()) for fn in data[1::3]]
sss = [ss.split(":")[-1].strip().split("/") for ss in data[2::3]]
print(list(map(lambda x: [float(x[0]), float(x[1][0]), float(x[1][1])], list(zip(fns, sss)))))
This will result in :
[[2.2, 1.0, 1806.0], [2.2, 1.0, 510.0], [2.2, 1.0, 374.0], [2.2, 1.0, 1884.0]]