I am working with a numpy array in python. I want to print the array and its properties to a txt output. I want the text output to end with a blank line. How can I do this?
I have tried:
# Create a text document of the output
with open("demo_numpy.txt","w") as text:
text.write('\n'.join(map(str, [a,shape,size,itemsize,ndim,dtype])) + '\n')
And also:
# Create a text document of the output
with open("demo_numpy.txt","w") as text:
text.write('\n'.join(map(str, [a,shape,size,itemsize,ndim,dtype])))
text.write('\n')
However, when I open the file in GitHub desktop, I still get the indication that the last line of the file is "dtype"
When you do "\n".join( ... ) you will get a string of the following form:
abc\ndef\nghi\nhjk
-- in other words, it won't end with \n.
If your code writes another \n then your string will be of the form
abc\ndef\nghi\nhjk\n
But that does not put a blank line at the end of your file because textfiles are supposed to have lines that end in \n. That is what the Posix standard says.
So you need another \n so that the last two lines of your file are
hjk\n
\n
Python will not choke if you ask it to read a textfile where the final trailing \n is missing. But it also won't treat a single trailing \n in a textfile as a blank line. It would not surprise me to learn that GitHub does likewise.
This was solved using the Python 3.x print function, which automatically inserts a new line at the end of each print statement.
Here is the code:
with open("demo_numpy.txt","w") as text:
print(a, file = text)
text.close()
Note- apparently it is more appropriate to use the print function rather than .write when dealing with string values as opposed to binary files.
Related
I have some stuff in an Excel spreadsheet, which is loaded into a webpage, where the content is displayed. However, what I have noticed is, that some of the content has weird formatting, i.e. a sudden line shift or something.
Then I just tried to copy the text from the spreadsheet, and pasting it into Notepad++, and enabled "Show White Space and Tab", and then the output was this:
The second line is the one directly copied from the spreadsheet, where the first one is just where I copied the string into a variable in Python, printed it, and then copied the output from the output console.
And as you can see the first line has all dots for space, where the other misses some dots. And I have an idea that that is what is doing this trickery, especially because it's at those place the line shift happens.
I have tried to just do something like:
import pandas as pd
data = pd.read_excel("my_spreadsheet.xlsx")
data["Strings"] = [str(x).replace(" ", " ") for x in data["Strings"]]
data.to_excel("my_spreadsheet.xlsx", index=False)
But that didn't change anything, as if I copied it straight from the output console.
So yeah, is there any easy way to make spaces the same type of spaces, or do I have to do something else ?
I think you would need to figure out which exact character is being used there.
You can load the file and print out the characters one by one together with the character code to figure out what's what.
See the code example below. I added some code to skip alphanumeric characters to reduce the actual output somewhat...
with open("filename.txt") as infile:
text = infile.readlines()
def print_ordinal(text: str, skip_alphanum: bool=True):
for line in text:
for character in line:
if not(skip_alphanum and character.isalnum()):
print(f"{character} - {ord(character)}")
print_ordinal(text)
I am trying to write code that compares variable b with value retrieved from text file using linecache.getline
The problem is it will never print our "ITS WORKING" because the values never match, even if they do :-(
THE TEXT FILE: In the text file there is only one character and its "a"
Here is the code:
import linecache
b="a"
a=linecache.getline("TextFile.txt",1)
if a==b:
print("ITS WORKING")
According to the documentation, linecache.getline will include the trailing newline character, that's why your match does not work.
You probably need to strip the extra spaces at the end of line that is read.
a=linecache.getline("TextFile.txt",1).strip()
Keerthana:~ kiran$ cat TextFile.txt
a
Keerthana:~ kiran$ py Desktop/test.py
a
ITS WORKING
Keerthana:~ kiran$
Hope it helps!
Trying to search for a string (email address) and print the line it is found in within a 1.66 gig .dump file(ashley madison). If I change print (line) to print ('true'), i get true returned, so i know it is reading the file, but when I try to print the line, python crashes with no error. Please help. python 3.4 on windows vista (rather than using a database and importing, I'm using this as a learning exercize for python)
import os
with open('aminno_member_email.dump', 'r', errors = 'ignore')as searchfile:
for line in searchfile:
if 'email#address.com' in line:
#print ('true')
print (line)
As I suspected, each line of that file is very long (to the tune of nearly a million characters, as you found). Most consoles are not set up to handle that sort of thing, so writing that line to a text file is your best bet. You can then open the file in a text editor or word processor and use its search function to locate areas of interest.
To display your search string with some characters of surrounding text, you can use a regular expression.
import re
...
# replace this:
'''
if 'email#address.com' in line:
#print ('true')
print (line)
'''
# with this:
print(*re.findall(r'(.{0,10}email#address\.com.{0,10})', line), sep='\n')
That will print each match with up to 10 characters before and after the search string, separated by a newline.
Example:
>>> print(*re.findall(r'(.{0,10}str.{0,10})', 'hello this is a string with text and it is very strong stuff'), sep='\n')
this is a string with t
t is very strong stuff
Open the file as stream instead and read from the stream instead of loading the entire file to RAM. Use io from the Python standard library.
with io.open('aminno_member_email.dump', 'r') as file:
...
I've got some python code which is getting line endings all wrong:
command = 'svn cat -r {} "{}{}"'.format(svn_revision, svn_repo, svn_filename)
content = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE).stdout.read()
written = False
for line in fileinput.input(out_filename, inplace=1):
if line.startswith("INPUT_TAG") and not written:
print content
written = True
print line,
This fetches a copy of the file called svn_filename, and inserts the content into another file called out_filename at the "INPUT_TAG" location in the file.
The problem is the line endings in out_filename.
They're meant to be \r\n but the block I insert is \r\r\n.
Changing the print statement to:
print content, # just removes the newlines after the content block
or
print content.replace('\r\r','\r') # no change
has no effect. The extra carriage returns are inserted after the content leaves my code. It seems like something is deciding that because I'm on windows it should convert all \n to \r\n.
How can I get around this?
I can "solve" this problem by doing the following:
content = content.replace('\r\n', '\n')
converting the newlines to unix style so when the internal magic converts it again it ends up correct.
This can't be the right/best/pythonic way though....
CRLF = Carriage Return Line Feed.
Python on Windows makes a distinction between text and binary files;
the end-of-line characters in text files are automatically altered
slightly when data is read or written.
https://docs.python.org/2/tutorial/inputoutput.html#reading-and-writing-files
Can you output as binary file and not as a text file?
If you prefix the string with r to open the file as raw, does this prevent extra \r in the output?
I'm trying to replace some text in a file with a value. Everything works fine but when I look at the file after its completed there is a new (blank) line after each line in the file. Is there something I can do to prevent this from happening.
Here is the code as I have it:
import fileinput
for line in fileinput.FileInput("testfile.txt",inplace=1):
line = line.replace("newhost",host)
print line
Thank you,
Aaron
Each line is read from the file with its ending newline, and the print adds one of its own.
You can:
print line,
Which won't add a newline after the line.
The print line automatically adds a newline. You'd best do a sys.stdout.write(line) instead.
print adds a new-line character:
A '\n' character is written at the end, unless the print statement ends with a comma. This is the only action if the statement contains just the keyword print.