I have a file with a bunch of numbers that have white spaces and colons and I am trying to remove them. As I have seen on this forum the function line.strip.split() works well to achieve this. Is there a way of removing the white space and colon all in one go? Using the method posted by Lorenzo I have this:
train = []
with open('C:/Users/Morgan Weiss/Desktop/STA5635/DataSets/dexter/dexter_train.data') as train_data:
train.append(train_data.read().replace(' ','').replace(':',''))
size_of_train = np.shape(train)
for i in range(size_of_train[0]):
for j in range(size_of_train[1]):
train[i][j] = int(train[i][j])
print(train)
Although I get this error:
File "C:/Users/Morgan Weiss/Desktop/STA5635/Homework/Homework_1/HW1_Dexter.py", line 11, in <module>
for j in range(size_of_train[1]):
IndexError: tuple index out of range
I think the above syntax is not correct, but anyways as per your question, you can use replace function present in python.
When reading each line as a string from that file you can do something like,
train = []
with open('/Users/sushant.moon/Downloads/dexter_train.data') as f:
list = f.read().split()
for x in list:
data = x.split(':')
train.append([int(data[0]),int(data[1])])
# this part becomes redundant as i have already converted str to int before i append data to train
size_of_train = np.shape(train)
for i in range(size_of_train[0]):
for j in range(size_of_train[1]):
train[i][j] = int(train[i][j])
Here I am using replace function to replace space with blank string, and similar with colon.
You did not provide an example of what your input file looks like so we can only speculate what solution you need. I'm going to suppose that you need to extract integers from your input text file and print their values.
Here's how I would do it:
Instead of trying to eliminate whitespace characters and colons, I will be searching for digits using a regular expression
Consecutive digits would constitute a number
I would convert this number to an integer form.
And here's how it would look like:
import re
input_filename = "/home/evens/Temporaire/Stack Exchange/StackOverflow/Input_file-39359816.txt"
matcher = re.compile(r"\d+")
with open(input_filename) as input_file:
for line in input_file:
for digits_found in matcher.finditer(line):
number_in_string_form = digits_found.group()
number = int(number_in_string_form)
print(number)
But before you run away with this code, you should continue to learn Python because you don't seem to grasp its basic elements yet.
Related
I'm trying to get all the substrings under a "customLabel" tag, for example "Month" inside of ...,"customLabel":"Month"},"schema":"metric...
Unusual issue: this is a 1071552 characters long ndjson file, of a single line ("for line in file:" is pointless since there's only one).
The best I found was that:
How to find a substring of text with a known starting point but unknown ending point in python
but if I use this, the result obviously doesn't stop (at Month) and keeps writing the whole remaining of the file, same as if using partition()[2].
Just know that Month is only an example, customLabel has about 300 variants and they are not listed (I'm actually doing this to list them...)
To give some details here's my script so far:
with open("file.ndjson","rt", encoding='utf-8') as ndjson:
filedata = ndjson.read()
x="customLabel"
count=filedata.count(x)
for i in range (count):
if filedata.find(x)>0:
print("Found "+str(i+1))
So right now it properly tells me how many occurences of customLabel there are, I'd like to get the substring that comes after customLabel":" instead (Month in the example) to put them all in a list, to locate them way more easily and enable the use of replace() for traductions later on.
I'd guess regex are the solution but I'm pretty new to that, so I'll post that question by the time I learn about them...
If you want to search for all (even nested) customLabel values like this:
{"customLabel":"Month" , "otherJson" : {"customLabel" : 23525235}}
you can use RegEx patterns with the re module
import re
label_values = []
regex_pattern = r"\"customLabel\"[ ]?:[ ]?([1-9a-zA-z\"]+)"
with open("file.ndjson", "rt", encoding="utf-8") as ndjson:
for line in ndjson:
values = re.findall(regex_pattern, line)
label_values.extend(values)
print(label_values) # ['"Month"', '23525235']
# If you don't want the items to have quotations
label_values = [i.replace('"', "") for i in label_values]
print(label_values) # ['Month', '23525235']
Note: If you're only talking about ndjson files and not nested searching, then it'd be better to use the json module to parse the lines and then easily get the value of your specific key which is customLabel.
import json
label = "customLabel"
label_values = []
with open("file.ndjson", "rt", encoding="utf-8") as ndjson:
for line in ndjson:
line_json = json.loads(line)
if line_json.get(label) is not None:
label_values.append(line_json.get(label))
print(label_values) # ['Month']
I have the following line of code reading in a specific part of a text file. The problem is these are numbers not strings so I want to convert them to ints and read them into a list of some sort.
A sample of the data from the text file is as follows:
However this is not wholly representative I have uploaded the full set of data here: http://s000.tinyupload.com/?file_id=08754130146692169643 as a text file.
*NSET, NSET=Nodes_Pushed_Back_IB
99915527, 99915529, 99915530, 99915532, 99915533, 99915548, 99915549, 99915550,
99915551, 99915552, 99915553, 99915554, 99915555, 99915556, 99915557, 99915558,
99915562, 99915563, 99915564, 99915656, 99915657, 99915658, 99915659, 99915660,
99915661, 99915662, 99915663, 99915664, 99915665, 99915666, 99915667, 99915668,
99915669, 99915670, 99915885, 99915886, 99915887, 99915888, 99915889, 99915890,
99915891, 99915892, 99915893, 99915894, 99915895, 99915896, 99915897, 99915898,
99915899, 99915900, 99916042, 99916043, 99916044, 99916045, 99916046, 99916047,
99916048, 99916049, 99916050
*NSET, NSET=Nodes_Pushed_Back_OB
Any help would be much appreciated.
Hi I am still stuck with this issue any more suggestions? Latest code and error message is as below Thanks!
import tkinter as tk
from tkinter import filedialog
file_path = filedialog.askopenfilename()
print(file_path)
data = []
data2 = []
data3 = []
flag= False
with open(file_path,'r') as f:
for line in f:
if line.strip().startswith('*NSET, NSET=Nodes_Pushed_Back_IB'):
flag= True
elif line.strip().endswith('*NSET, NSET=Nodes_Pushed_Back_OB'):
flag= False #loop stops when condition is false i.e if false do nothing
elif flag: # as long as flag is true append
data.append([int(x) for x in line.strip().split(',')])
result is the following error:
ValueError: invalid literal for int() with base 10: ''
Instead of reading these as strings I would like each to be a number in a list, i.e [98932850 98932852 98932853 98932855 98932856 98932871 98932872 98932873]
In such cases I use regular expressions together with string methods. I would solve this problem like so:
import re
with open(filepath) as f:
txt = f.read()
g = re.search(r'NSET=Nodes_Pushed_Back_IB(.*)', txt, re.S)
snums = g.group(1).replace(',', ' ').split()
numbers = [int(num) for num in snums]
I read the entire text into txt.
Next I use a regular expression and use the last portion of your header in the text as an anchor, and capture with capturing parenthesis all the rest (the re.S flag means that a dot should capture also newlines). I access all the nubers as one unit of text via g.group(1).
Next. I remove all the commas (actually replace them with spaces) because on the resulting text I use split() which is an excellent function to use on text items that are separated with spaces - it doesn't matter the amount of spaces, it just splits it as you would intent.
The rest is just converting the text to numbers using a list comprehension.
Your line contains more than one number, and some separating characters. You could parse that format by judicious application of split and perhaps strip, or you could minimize string handling by having re extract specifically the fields you care about:
ints = list(map(int, re.findall(r'-?\d+', line)))
This regular expression will find each group of digits, optionally prefixed by a minus sign, and then map will apply int to each such group found.
Using a sample of your string:
strings = ' 98932850, 98932852, 98932853, 98932855, 98932856, 98932871, 98932872, 98932873,\n'
I'd just split the string, strip the commas, and return a list of numbers:
numbers = [ int(s.strip(',')) for s in strings.split() ]
Based on your comment and regarding the larger context of your code. I'd suggest a few things:
from itertools import groupby
number_groups = []
with open('data.txt', 'r') as f:
for k, g in groupby(f, key=lambda x: x.startswith('*NSET')):
if k:
pass
else:
number_groups += list(filter('\n'.__ne__, list(g))) #remove newlines in list
data = []
for group in number_groups:
for str_num in group.strip('\n').split(','):
data.append(int(str_num))
I'm still learning Python, and I have a question I haven't been able to solve. I have a very long string (millions of lines long) which I would like to be split into a smaller string length based on a specified number of occurrences of a delimeter.
For instance:
ABCDEF
//
GHIJKLMN
//
OPQ
//
RSTLN
//
OPQR
//
STUVW
//
XYZ
//
In this case I would want to split based on "//" and return a string of all lines before the nth occurrence of the delimeter.
So an input of splitting the string by // by 1 would return:
ABCDEF
an input of splitting the string by // by 2 would return:
ABCDEF
//
GHIJKLMN
an input of splitting the string by // by 3 would return:
ABCDEF
//
GHIJKLMN
//
OPQ
And so on... However, The length of the original 2 million line string appeared to be a problem when I simply tried to split the entire string and by "//" and just work with the individual indexes. (I was getting a memory error) Perhaps Python can't handle so many lines in one split? So I can't do that.
I'm looking for a way that I don't need to split the entire string into a hundred-thousand indexes when I may only need 100, but instead just start from the beginning until a certain point, stop and return everything before it, which I assume may also be faster? I hope my question is as clear as possible.
Is there a simple or elegant way to achieve this? Thanks!
If you want to work with files instead of strings in memory, here is another answer.
This version is written as a function that reads lines and immediately prints them out until the specified number of delimiters have been found (no extra memory needed to store the entire string).
def file_split(file_name, delimiter, n=1):
with open(file_name) as fh:
for line in fh:
line = line.rstrip() # use .rstrip("\n") to only strip newlines
if line == delimiter:
n -= 1
if n <= 0:
return
print line
file_split('data.txt', '//', 3)
You can use this to write the output to a new file like this:
python split.py > newfile.txt
With a little extra work, you can use argparse to pass parameters to the program.
As a more efficient way you can read the firs N lines separated by your delimiter so if you are sure that all of your lines are splitted by delimiter you can use itertools.islice to do the job:
from itertools import islice
with open('filename') as f :
lines = islice(f,0,2*N-1)
The method that comes to my mind when I read your question uses a for loop
where you cut up the string into several (for example the 100 you called) and iterate through the substring.
thestring = "" #your string
steps = 100 #length of the strings you are going to use for iteration
log = 0
substring = thestring[:log+steps] #this is the string you will split and iterate through
thelist = substring.split("//")
for element in thelist:
if(element you want):
#do your thing with the line
else:
log = log+steps
# and go again from the start only with this offset
now you can go through all the elements go through the whole 2 million(!) line string.
best thing to do here is actually make a recursive function from this(if that is what you want):
thestring = "" #your string
steps = 100 #length of the strings you are going to use for iteration
def iterateThroughHugeString(beginning):
substring = thestring[:beginning+steps] #this is the string you will split and iterate through
thelist = substring.split("//")
for element in thelist:
if(element you want):
#do your thing with the line
else:
iterateThroughHugeString(beginning+steps)
# and go again from the start only with this offset
For instance:
i = 0
s = ""
fd = open("...")
for l in fd:
if l[:-1] == delimiter: # skip last '\n'
i += 1
if i >= max_split:
break
s += l
fd.close()
Since you are learning Python it would be a challenge to model a complete dynamic solution. Here's a notion of how you can model one.
Note: The following code snippet only works for file(s) which is/are in the given format (see the 'For Instance' in the question). Hence, it is a static solution.
num = (int(input("Enter delimiter: ")) * 2)
with open("./data.txt") as myfile:
print ([next(myfile) for x in range(num-1)])
Now that have the idea, you can use pattern matching and so on.
I have a log file and at the end of each line in the file there is this string:
Line:# where # is the line number.
I am trying to get the # and compare it to the previous line's number. what would be the best way to do that in python?
I would probably use str.split because it seems easy:
with open('logfile.log') as fin:
numbers = [ int(line.split(':')[-1]) for line in fin ]
Now you can use zip to compare one number with the next one:
for num1,num2 in zip(numbers,numbers[1:]):
compare(num1,num2) #do comparison here.
Of course, this isn't lazy (you store every line number in the file at once when you really only need 2 at a time), so it might take up a lot of memory if your files are HUGE. It wouldn't be hard to make it lazy though:
def elem_with_next(iterable):
ii = iter(iterable)
prev = next(ii)
for here in ii:
yield prev,here
prev = here
with open('logfile.log') as fin:
numbers = ( int(line.split(':')[-1]) for line in fin )
for num1,num2 in elem_with_next(numbers):
compare(num1,num2)
I'm assuming that you don't have something convenient to split a string on, meaning a regular expression might make more sense. That is, if the lines in your log file are structured like:
date: 1-15-2013, error: mildly_annoying, line: 121
date: 1-16-2013, error: err_something_bad, line: 123
Then you won't be able to use line.split('#') as mgilson as suggested, although if there is always a colon, line.split(':') might work. In any case, a regular expression solution would look like:
import re
numbers = []
for line in log:
digit_match = re.search("(\d+)$", line)
if digit_match is not None:
numbers.append(int(digit_match.group(1)))
Here the expression "(\d+)$" is matching some number of digits and then the end of the line. We extract the digits with the group(1) method on the returned match object and then add them to our list of line numbers.
If you're not confident that the "Line: #" will always come at the end of the log, you could replace the regular expression used above with something akin to "Line:\s*(\d+)" which checks for the string "Line:" then some (or no) whitespace, and then any number of digits.
Program Details:
I am writing a program for python that will need to look through a text file for the line:
Found mode 1 of 12: EV= 1.5185449E+04, f= 19.612545, T= 0.050988.
Problem:
Then after the program has found that line, it will then store the line into an array and get the value 19.612545, from f = 19.612545.
Question:
I so far have been able to store the line into an array after I have found it. However I am having trouble as to what to use after I have stored the string to search through the string, and then extract the information from variable f. Does anyone have any suggestions or tips on how to possibly accomplish this?
Depending upon how you want to go at it, CosmicComputer is right to refer you to Regular Expressions. If your syntax is this simple, you could always do something like:
line = 'Found mode 1 of 12: EV= 1.5185449E+04, f= 19.612545, T= 0.050988.'
splitByComma=line.split(',')
fValue = splitByComma[1].replace('f= ', '').strip()
print(fValue)
Results in 19.612545 being printed (still a string though).
Split your line by commas, grab the 2nd chunk, and break out the f value. Error checking and conversions left up to you!
Using regular expressions here is maddness. Just use string.find as follows: (where string is the name of the variable the holds your string)
index = string.find('f=')
index = index + 2 //skip over = and space
string = string[index:] //cuts things that you don't need
string = string.split(',') //splits the remaining string delimited by comma
your_value = string[0] //extracts the first field
I know its ugly, but its nothing compared with RE.