Python String Wrap - python

I want to wrap the string at 30,700 in this script. What is the best way of doing this, I have tried using textWrap but it does not seem to work. This is my code:
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas
canvas = canvas.Canvas("Forensic Report.pdf", pagesize=letter)
canvas.setLineWidth(.3)
canvas.setFont('Helvetica', 12)
canvas.drawString(30,750,'LYIT MOBILE FORENSICS DIVISION')
canvas.drawString(500,750,"Date: 12/02/2018")
canvas.line(500,747,595,747)
canvas.drawString(500,725,'Case Number:')
canvas.drawString(580,725,"10")
canvas.line(500,723,595,723)
canvas.drawString(30, 700, 'This forensic report has been compiled by the forensic examiner in conclusion to the investigation into the RTA case which occured on 23/01/2018')
canvas.save()
print("Forensic Report Generated")

Perhaps you want to use the drawText?
Doing so, your code will be
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas
canvas = canvas.Canvas("Forensic Report.pdf", pagesize=letter)
canvas.setLineWidth(.3)
canvas.setFont('Helvetica', 12)
canvas.drawString(30,750,'LYIT MOBILE FORENSICS DIVISION')
canvas.drawString(500,750,"Date: 12/02/2018")
canvas.line(500,747,595,747)
canvas.drawString(500,725,'Case Number:')
canvas.drawString(580,725,"10")
canvas.line(500,723,595,723)
line1 = 'This forensic report has been compiled by the forensic'
line2 = 'examiner in conclusion to the investigation into the RTA'
line3 = 'case which occured on 23/01/2018'
textobject = canvas.beginText(30, 700)
lines = [line1, line2, line3]
for line in lines:
textobject.textLine(line)
canvas.drawText(textobject)
canvas.save()
This is also the solution suggested here. Unfortunately, I do not see it as a valid solution for automatic text wrapping in new lines, i.e. you should manage how to split the string yourself.

You should wrap the string itself using a function and draw what's returned. To get a properly wrapped string you could specify a line length like so:
def wrap(string, length):
if len(string) < length:
return string
return string[:length:] + '\n' + wrap(string[length::], length)
The wrap function first checks if the string length is less than the specified length and immediately returns it if so. If it's longer then it appends a newline character to the end of a substring up to length, plus sends the remainder of the string to the wrap() function to check the rest.
Running:
string = "This is a really super duper long string from some forensic report and should take up a lot of space..."
length = 20
print(wrap(string, length))
Will print out:
This is a really sup
er duper long string
from some forensic
report and should ta
ke up a lot of space
...
Because you PROBABLY don't want every single line to be truncated at the line width, we can fix this by adding another recursive function to check for the most recent whitespace character like so:
def seek(string, index):
if string[index-1] == ' ':
return index
return seek(string, index-1)
The seek() will return the index of the last whitespace character of any string (substring in this case).
Note: seek() HAS to check the previous character string[index-1] otherwise will give you the index of the space character and wrap() will append it to each new line.
You can then modify the wrap() function like so:
def wrap(string, length):
if len(string) < length:
return string
pos = seek(string, length)
return string[:pos:] + '\n' + wrap(string[pos::], length)
Running:
string = "This is a really super duper long string from some forensic report and should take up a lot of space..."
length = 20
print(wrap(string, length))
Prints out:
This is a really
super duper long
string from some
forensic report and
should take up a
lot of space...

Related

What causes this return() to create a SyntaxError?

I need this program to create a sheet as a list of strings of ' ' chars and distribute text strings (from a list) into it. I have already coded return statements in python 3 but this one keeps giving
return(riplns)
^
SyntaxError: invalid syntax
It's the return(riplns) on line 39. I want the function to create a number of random numbers (randint) inside a range built around another randint, coming from the function ripimg() that calls this one.
I see clearly where the program declares the list I want this return() to give me. I know its type. I see where I feed variables (of the int type) to it, through .append(). I know from internet research that SyntaxErrors on python's return() functions usually come from mistype but it doesn't seem the case.
#loads the asciified image ("/home/userX/Documents/Programmazione/Python projects/imgascii/myascify/ascimg4")
#creates a sheet "foglio1", same number of lines as the asciified image, and distributes text on it on a randomised line
#create the sheet foglio1
def create():
ref = open("/home/userX/Documents/Programmazione/Python projects/imgascii/myascify/ascimg4")
charcount = ""
field = []
for line in ref:
for c in line:
if c != '\n':
charcount += ' '
if c == '\n':
charcount += '*' #<--- YOU GONNA NEED TO MAKE THIS A SPACE IN A FOLLOWING FUNCTION IN THE WRITER.PY PROGRAM
for i in range(50):#<------- VALUE ADJUSTMENT FROM WRITER.PY GOES HERE(default : 50):
charcount += ' '
charcount += '\n'
break
for line in ref:
field.append(charcount)
return(field)
#turn text in a list of lines and trasforms the lines in a list of strings
def poemln():
txt = open("/home/gcg/Documents/Programmazione/Python projects/imgascii/writer/poem")
arrays = []
for line in txt:
arrays.append(line)
txt.close()
return(arrays)
#rander is to be called in ripimg()
def rander(rando, fldepth):
riplns = []
for i in range(fldepth):
riplns.append(randint((rando)-1,(rando)+1)
return(riplns) #<---- THIS RETURN GIVES SyntaxError upon execution
#opens a rip on the side of the image.
def ripimg():
upmost = randint(160, 168)
positions = []
fldepth = 52 #<-----value is manually input as in DISTRIB function.
positions = rander(upmost,fldepth)
return(positions)
I omitted the rest of the program, I believe these functions are enough to get the idea, please tell me if I need to add more.
You have incomplete set of previous line's parenthesis .
In this line:-
riplns.append(randint((rando)-1,(rando)+1)
You have to add one more brace at the end. This was causing error because python was reading things continuously and thought return statement to be a part of previous uncompleted line.

Using function returns with None

Write a function file_in_english(filename, character_limit) that takes a filename (as a str) and a character_limit (as an int). The filename is the name of the file to convert from Cat Latin to English and the character limit is the maximum number of characters that can be converted. The limit is on the total number of characters in the output (including newline characters).
The function should return a string that contains all the converted lines in the same order as the file - remember the newline character at the end of each line (that is make sure you include a newline character at the end of each converted line so that it is included in the line's length).
If the limit is exceeded (ie, a converted sentence would take the output over the limit) then the sentence that takes the character count over the limit shouldn't be added to the output. A line with "<>" should be added at the end of the output instead. The processing of lines should then stop.
The lines in the file will each be a sentence in Weird Latin and your program should print out the English version of each sentence
The function should keep adding sentences until it runs out of input from the file or the total number of characters printed (including spaces) exceeds the limit.
The answer must include your definition of english_sentence and its helper(s) functions - that I should have called english_word or similar.
You MUST use while in your file_in_english function.
You can only use one return statement per function.
The test file used in the examples (test1.txt) has the following data:
impleseeoow estteeoow aseceeoow
impleseeoow estteeoow aseceeoow ineleeoow 2meeoow
impleseeoow estteeoow aseceeoow ineleeoow 3meeoow
impleseeoow estteeoow aseceeoow ineleeoow 4meeoow
I program works fine except that sometimes it returns None.
def english_sentence(sentence):
"""Reverse Translation"""
consonants = 'bcdfghjklmnpqrstvwxyzBCDFGHJKLMNPQRSTVWXYZ'
eng_sentence = []
for coded_word in sentence.split():
if coded_word.endswith("eeoow") and (coded_word[-6] in consonants):
english_word = coded_word[-6] + coded_word[:-6]
if (coded_word[-6] == 'm') and (coded_word[0] not in consonants):
english_word = '(' + english_word + ' or ' + coded_word[:-6] + ')'
eng_sentence.append(english_word)
return " ".join(eng_sentence)
def file_in_english(filename, character_limit):
"""English File"""
newone = open(filename)
nowline = newone.readline()
characters = 0
while characters < character_limit and nowline != "":
process = nowline[0:-1]
print(english_sentence(process))
characters += len(nowline)
nowline = newone.readline()
if characters > character_limit:
return("<<Output limit exceeded>>")
ans = file_in_english('test1.txt', 20)
print(ans)
Output is:
simple test case
simple test case line (m2 or 2)
simple test case line (m3 or 3)
simple test case line (m4 or 4)
None
But I must use only one return statement in each function. How can I do that for the second function and avoid the "None" in output?
You're doing the same thing as:
def f():
print('hello')
print(f())
So basically narrows down to:
print(print('hello world'))
Also btw:
>>> type(print('hello'))
hello
<class 'NoneType'>
>>>
To solve your code do:
def file_in_english(filename, character_limit):
s=""
"""English File"""
newone = open(filename)
nowline = newone.readline()
characters = 0
while characters < character_limit and nowline != "":
process = nowline[0:-1]
s+=english_sentence(process)+'\n'
characters += len(nowline)
nowline = newone.readline()
if characters > character_limit:
s+="<<Output limit exceeded>>"
return s
ans = file_in_english('test1.txt', 20)
print(ans)
You have to make sure, that any function that should return something, does this for ALL ways that your function can end.
Your function file_in_english only returns something for the case if characters > character_limit:
If charachter == or charachter < character_limit this is not the case, the function returns nothing explicitly.
Any function that does not return something from it on end, implicitly returns None when it returns to its caller.
def something(boolean):
"""Function that only returns something meaninfull if boolean is True."""
if boolean:
return "Wow"
print(something(True)) # returns Wow
print(something(False)) # implicitly returns/prints None
You can find this fact f.e. in the python tutorial:
Coming from other languages, you might object that fib is not a
function but a procedure since it doesn’t return a value. In fact,
even functions without a return statement do return a value, albeit a
rather boring one. This value is called None (it’s a built-in name).
Writing the value None is normally suppressed by the interpreter if it
would be the only value written. You can see it if you really want to
using print():
Source:https://docs.python.org/3.7/tutorial/controlflow.html#defining-functions - just short after the 2nd green example box

Read Null terminated string in python

I'm trying to read a null terminated string but i'm having issues when unpacking a char and putting it together with a string.
This is the code:
def readString(f):
str = ''
while True:
char = readChar(f)
str = str.join(char)
if (hex(ord(char))) == '0x0':
break
return str
def readChar(f):
char = unpack('c',f.read(1))[0]
return char
Now this is giving me this error:
TypeError: sequence item 0: expected str instance, int found
I'm also trying the following:
char = unpack('c',f.read(1)).decode("ascii")
But it throws me:
AttributeError: 'tuple' object has no attribute 'decode'
I don't even know how to read the chars and add it to the string, Is there any proper way to do this?
Here's a version that (ab)uses __iter__'s lesser-known "sentinel" argument:
with open('file.txt', 'rb') as f:
val = ''.join(iter(lambda: f.read(1).decode('ascii'), '\x00'))
How about:
myString = myNullTerminatedString.split("\x00")[0]
For example:
myNullTerminatedString = "hello world\x00\x00\x00\x00\x00\x00"
myString = myNullTerminatedString.split("\x00")[0]
print(myString) # "hello world"
This works by splitting the string on the null character. Since the string should terminate at the first null character, we simply grab the first item in the list after splitting. split will return a list of one item if the delimiter doesn't exist, so it still works even if there's no null terminator at all.
It also will work with byte strings:
myByteString = b'hello world\x00'
myStr = myByteString.split(b'\x00')[0].decode('ascii') # "hello world" as normal string
If you're reading from a file, you can do a relatively larger read - estimate how much you'll need to read to find your null string. This is a lot faster than reading byte-by-byte. For example:
resultingStr = ''
while True:
buf = f.read(512)
resultingStr += buf
if len(buf)==0: break
if (b"\x00" in resultingStr):
extraBytes = resultingStr.index(b"\x00")
resultingStr = resultingStr.split(b"\x00")[0]
break
# now "resultingStr" contains the string
f.seek(0 - extraBytes,1) # seek backwards by the number of bytes, now the pointer will be on the null byte in the file
# or f.seek(1 - extraBytes,1) to skip the null byte in the file
(edit version 2, added extra way at the end)
Maybe there are some libraries out there that can help you with this, but as I don't know about them lets attack the problem at hand with what we know.
In python 2 bytes and string are basically the same thing, that change in python 3 where string is what in py2 is unicode and bytes is its own separate type, which mean that you don't need to define a read char if you are in py2 as no extra work is required, so I don't think you need that unpack function for this particular case, with that in mind lets define the new readString
def readString(myfile):
chars = []
while True:
c = myfile.read(1)
if c == chr(0):
return "".join(chars)
chars.append(c)
just like with your code I read a character one at the time but I instead save them in a list, the reason is that string are immutable so doing str+=char result in unnecessary copies; and when I find the null character return the join string. And chr is the inverse of ord, it will give you the character given its ascii value. This will exclude the null character, if its needed just move the appending...
Now lets test it with your sample file
for instance lets try to read "Sword_Wea_Dummy" from it
with open("sword.blendscn","rb") as archi:
#lets simulate that some prior processing was made by
#moving the pointer of the file
archi.seek(6)
string=readString(archi)
print "string repr:", repr(string)
print "string:", string
print ""
#and the rest of the file is there waiting to be processed
print "rest of the file: ", repr(archi.read())
and this is the output
string repr: 'Sword_Wea_Dummy'
string: Sword_Wea_Dummy
rest of the file: '\xcd\xcc\xcc=p=\x8a4:\xa66\xbfJ\x15\xc6=\x00\x00\x00\x00\xeaQ8?\x9e\x8d\x874$-i\xb3\x00\x00\x00\x00\x9b\xc6\xaa2K\x15\xc6=;\xa66?\x00\x00\x00\x00\xb8\x88\xbf#\x0e\xf3\xb1#ITuB\x00\x00\x80?\xcd\xcc\xcc=\x00\x00\x00\x00\xcd\xccL>'
other tests
>>> with open("sword.blendscn","rb") as archi:
print readString(archi)
print readString(archi)
print readString(archi)
sword
Sword_Wea_Dummy
ÍÌÌ=p=Š4:¦6¿JÆ=
>>> with open("sword.blendscn","rb") as archi:
print repr(readString(archi))
print repr(readString(archi))
print repr(readString(archi))
'sword'
'Sword_Wea_Dummy'
'\xcd\xcc\xcc=p=\x8a4:\xa66\xbfJ\x15\xc6='
>>>
Now that I think about it, you mention that the data portion is of fixed size, if that is true for all files and the structure on all of them is as follow
[unknow size data][know size data]
then that is a pattern we can exploit, we only need to know the size of the file and we can get both part smoothly as follow
import os
def getDataPair(filename,knowSize):
size = os.path.getsize(filename)
with open(filename, "rb") as archi:
unknown = archi.read(size-knowSize)
know = archi.read()
return unknown, know
and by knowing the size of the data portion, its use is simple (which I get by playing with the prior example)
>>> strins_data, data = getDataPair("sword.blendscn", 80)
>>> string_data, data = getDataPair("sword.blendscn", 80)
>>> string_data
'sword\x00Sword_Wea_Dummy\x00'
>>> data
'\xcd\xcc\xcc=p=\x8a4:\xa66\xbfJ\x15\xc6=\x00\x00\x00\x00\xeaQ8?\x9e\x8d\x874$-i\xb3\x00\x00\x00\x00\x9b\xc6\xaa2K\x15\xc6=;\xa66?\x00\x00\x00\x00\xb8\x88\xbf#\x0e\xf3\xb1#ITuB\x00\x00\x80?\xcd\xcc\xcc=\x00\x00\x00\x00\xcd\xccL>'
>>> string_data.split(chr(0))
['sword', 'Sword_Wea_Dummy', '']
>>>
Now to get each string a simple split will suffice and you can pass the rest of the file contained in data to the appropriated function to be processed
Doing file I/O one character at a time is horribly slow.
Instead use readline0, now on pypi: https://pypi.org/project/readline0/ . Or something like it.
In 3.x, there's a "newline" argument to open, but it doesn't appear to be as flexible as readline0.
Here is my implementation:
import struct
def read_null_str(f):
r_str = ""
while 1:
back_offset = f.tell()
try:
r_char = struct.unpack("c", f.read(1))[0].decode("utf8")
except:
f.seek(back_offset)
temp_char = struct.unpack("<H", f.read(2))[0]
r_char = chr(temp_char)
if ord(r_char) == 0:
return r_str
else:
r_str += r_char

Returning every instance of whatever's between two strings in a file [Python 3]

What I'm trying to do is open a file, then find every instance of '[\x06I"' and '\x06;', then return whatever is between the two.
Since this is not a standard text file (it's map data from RPG maker) readline() will not work for my purposes, as the file is not at all formatted in such a way that the data I want is always neatly within one line by itself.
What I'm doing right now is loading the file into a list with read(), then simply deleting characters from the very beginning until I hit the string '[\x06I'. Then I scan ahead to find '\x06;', store what's between them as a string, append said string to a list, then resume at the character after the semicolon I found.
It works, and I ended up with pretty much exactly what I wanted, but I feel like that's the worst possible way to go about it. Is there a more efficient way?
My relevant code:
while eofget == 0:
savor = 0
while savor == 0 or eofget == 0:
if line[0:4] == '[\x06I"':
x = 4
spork = 0
while spork == 0:
x += 1
if line[x] == '\x06':
if line[x+1] == ';':
spork = x
savor = line[5:spork] + "\n"
line = line[x+1:]
linefinal[lineinc] = savor
lineinc += 1
elif line[x:x+7] == '#widthi':
print("eof reached")
spork = 1
eofget = 1
savor = 0
elif line[x:x+7] == '#widthi':
print("finished map " + mapname)
eofget = 1
savor = 0
break
else:
line = line[1:]
You can just ignore the variable names. I just name things the first thing that comes to mind when I'm doing one-offs like this. And yes, I am aware a few things in there don't make any sense, but I'm saving cleanup for when I finalize the code.
When eofget gets flipped on this subroutine terminates and the next map is loaded. Then it repeats. The '#widthi' check is basically there to save time, since it's present in every map and indicates the beginning of the map data, AKA data I don't care about.
I feel this is a natural case to use regular expressions. Using the findall method:
>>> s = 'testing[\x06I"text in between 1\x06;filler text[\x06I"text in between 2\x06;more filler[\x06I"text in between \n with some line breaks \n included in the text\x06;ending'
>>> import re
>>> p = re.compile('\[\x06I"(.+?)\x06;', re.DOTALL)
>>> print(p.findall(s))
['text in between 1', 'text in between 2', 'text in between \n with some line breaks \n included in the text']
The regex string '\[\x06I"(.+?)\x06;'can be interpreted as follows:
Match as little as possible (denoted by ?) of an undetermined number of unspecified characters (denoted by .+) surrounded by '[\x06I"' and '\x06;', and only return the enclosed text (denoted by the parentheses around .+?)
Adding re.DOTALL in the compile makes the .? match line breaks as well, allowing multi-line text to be captured.
I would use split():
fulltext = 'adsfasgaseg[\x06I"thisiswhatyouneed\x06;sdfaesgaegegaadsf[\x06I"this is the second what you need \x06;asdfeagaeef'
parts = fulltext.split('[\x06I"') # split by first label
results = []
for part in parts:
if '\x06;' in part: # if second label exists in part
results.append(part.split('\x06;')[0]) # get the part until the second label
print results

Python Textwrap - forcing 'hard' breaks

I am trying to use textwrap to format an import file that is quite particular in how it is formatted. Basically, it is as follows (line length shortened for simplicity):
abcdef <- Ok line
abcdef
ghijk <- Note leading space to indicate wrapped line
lm
Now, I have got code to work as follows:
wrapper = TextWrapper(width=80, subsequent_indent=' ', break_long_words=True, break_on_hyphens=False)
for l in lines:
wrapline=wrapper.wrap(l)
This works nearly perfectly, however, the text wrapping code doesn't do a hard break at the 80 character mark, it tries to be smart and break on a space (at approx 20 chars in).
I have got round this by replacing all spaces in the string list with a unique character (#), wrapping them and then removing the character, but surely there must be a cleaner way?
N.B Any possible answers need to work on Python 2.4 - sorry!
A generator-based version might be a better solution for you, since it wouldn't need to load the entire string in memory at once:
def hard_wrap(input, width, indent=' '):
for line in input:
indent_width = width - len(indent)
yield line[:width]
line = line[width:]
while line:
yield '\n' + indent + line[:indent_width]
line = line[indent_width:]
Use it like this:
from StringIO import StringIO # Makes strings look like files
s = """abcdefg
abcdefghijklmnopqrstuvwxyz"""
for line in hard_wrap(StringIO(s), 12):
print line,
Which prints:
abcdefg
abcdefghijkl
mnopqrstuvw
xyz
It sounds like you are disabling most of the functionality of TextWrapper, and then trying to add a little of your own. I think you'd be better off writing your own function or class. If I understand you right, you're simply looking for lines longer than 80 chars, and breaking them at the 80-char mark, and indenting the remainder by one space.
For example, this:
s = """\
This line is fine.
This line is very long and should wrap, It'll end up on a few lines.
A short line.
"""
def hard_wrap(s, n, indent):
wrapped = ""
n_next = n - len(indent)
for l in s.split('\n'):
first, rest = l[:n], l[n:]
wrapped += first + "\n"
while rest:
next, rest = rest[:n_next], rest[n_next:]
wrapped += indent + next + "\n"
return wrapped
print hard_wrap(s, 20, " ")
produces:
This line is fine.
This line is very lo
ng and should wrap,
It'll end up on a
few lines.
A short line.

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