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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.

simple print statement is not working inside method with if statement in python

I started learning Python code recently and one simple print statement is giving me trouble since last 4 days.
Problem: the print statement is not working inside the validatePostcode(postcode) method for if-statement. The assigned value is 200 (status code) which is printing fine without the if-statement. Also, when I compare with the True (result value) for that API it works fine without if-statement, why it is not working after I apply the if and try to compare?
Error:
File "./py_script3.py", line 32
print ("Congrats")
^
IndentationError: expected an indented block
#!/usr/bin/env python3
import os,re,sys
import urllib.request as req
import json
def loadJsonResponse(url):
#return json.loads(req.urlopen(url).read().decode('utf-8'))['result']
#return json.loads(req.urlopen(url).read().decode('utf-8'))['status']
print ("I am in loadJsonResponse before returning string")
string = json.loads(req.urlopen(url).read().decode('utf-8'))
return string
print ("I am in loadJsonResponse after returning string")
def lookuppostcode(postcode):
url = 'https://api.postcodes.io/postcodes/{}'.format(postcode)
return loadJsonResponse(url)
def validatePostcode(postcode):
url = 'https://api.postcodes.io/postcodes/{}/validate'.format(postcode)
#return loadJsonResponse(url)
string = json.loads(req.urlopen(url).read().decode('utf-8'))
Value = str(string['status'])
print (Value)
if Value == 200 :
print ("Congrats")
def randomPostcode():
url = 'https://api.postcodes.io/random/postcodes'
return loadJsonResponse(url)
def queryPostcode(postcode):
url = 'https://api.postcodes.io/postcodes?q={}'.format(postcode)
return loadJsonResponse(url)
def getAutoCompletePostcode(postcode):
url = 'https://api.postcodes.io/postcodes/{}/autocomplete'.format(postcode)
return loadJsonResponse(url)
#Input = input("Enter the postcode : ")
#print(lookuppostcode('CB3 0FA'))
validatePostcode('CB3 0FA')
#print(queryPostcode('HU88BT'))
#print(randomPostcode(Input))

This piece of code (which is generating the error):
if Value == 200 :
print ("Congrats")
Should be
if Value == 200 :
print ("Congrats")
Because python expects an indented block after the conditional, just like the message error is saying to you

You should indent the print statement like so:
if Value == 200 :
print ("Congrats")
You can read more about this here!

From https://docs.python.org/2.0/ref/indentation.html:
Leading whitespace (spaces and tabs) at the beginning of a logical line is used to compute the indentation level of the line, which in turn is used to determine the grouping of statements.
By doing
if Value == 200:
print ("Congrats")
Python interprets the two lines as two different groups of statements. What you should do is:
if Value == 200:
print ("Congrats")

Need to add an indent after the if statement. You can do so by pressing return after typing the colon

After the if-statement, a section of code to run when the condition is True is included. The section of must be indented and every line in this section of code must be indented the same number of spaces. By convention, four space indentation is used in Python.
if Value == 200:
print ("Congrats")

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

Appending print commands with .decode() method

I have a script of about 300 lines (part of which is pasted below) with a lot of print commands. I am trying to cleanup the output it produces. If I leave it the way it is then all the print commands print bytes with \r\n on to the console.
I figured if I add .decode('utf-8') in front of the variable that I need to print then the output is what I should be expecting (uni-code string). For example, compare print (data1) and print (data3) commands below. What I want to do is to go through all of the code and append .decode() to every print statement.
All the print commands are in this format: Print (dataxxxx)
import telnetlib
import time
import sys
import random
from xlwt import Workbook
shelfIp = "10.10.10.10"
shelf = "33"
print ("Shelf IP is: " + str(shelfIp))
print ("Shelf number is: " + str(shelf))
def addCard():
tn = telnetlib.Telnet(shelfIp)
### Telnet session
tn.read_until(b"<",5)
cmd = "ACT-USER::ADMIN:ONE::ADMIN;"
tn.write(bytes(cmd,encoding="UTF-8"))
data1 = tn.read_until(b"ONE COMPLD", 5)
print (data1.decode('utf-8'))
### Entering second network element
cmd = "ENT-CARD::CARD" + shelf + "-" + shelf + ":TWO:xyz:;"
tn.write(bytes(cmd,encoding="UTF-8"))
data3 = tn.read_until(b"TWO COMPLD", 5)
print (data3)
### Entering third network element
cmd = "ENT-CARD::CARD-%s-%s:ADM:ABC:;" %(shelf,shelf)
tn.write(bytes(cmd,encoding="UTF-8"))
dataAmp = tn.read_until(b"ADM COMPLD", 5)
print (dataAmp)
tn.close()
addCard()

If you are looking into doing some sort of find-replace on the code, you can try this:
import re
f = open('script.py','rb')
script = f.read()
f.close()
newscript = re.sub("(print\(.*)\)", "\g<1>.decode('utf-8'))", script)
f = open('script.py', 'wb')
f.write(newscript)
f.close()
What I did in the regular expression:
Catch text that contains print(......) and save the print(..... part into group 1
Replace the text after the print(.... which is ) with: .decode('utf-8')) using the syntax \g<1> which takes the saved group number 1 and put that as the prefix in the replaced text.

Appending .decode() to print() statements will fail because .decode() is a string method.
>>> x=u"testing"
>>> print(x).decode('utf-8')
testing
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: 'NoneType' object has no attribute 'decode'
You must apply .decode('utf-8') to the variables you wish to decode, which is not easily accomplished using regex based tools.

Two regex functions together do not work

I am trying to get the index for the start of a tag and the end of another tag. However, when I use one regex it works absolutely fine but for two regex functions, it gives an error for the second one.
Kindly help in explaining the reason
The below code works fine:
import re
f = open('C:/Users/Jyoti/Desktop/PythonPrograms/try.xml','r')
opentag = re.search('<TEXT>',f.read())
begin = opentag.start()+6
print begin
But when I add another similar regex it give me the error
AttributeError: 'NoneType' object has no attribute 'start'
which I understand is due to the start() function returning None
Below is the code:
import re
f = open('C:/Users/Jyoti/Desktop/PythonPrograms/try.xml','r')
opentag = re.search('<TEXT>',f.read())
begin = opentag.start()+6
print begin
closetag = re.search('</TEXT>',f.read())
end = closetag.start() - 1
print end
Please provide a solution to how can I get this working. Also I am a newbie here so please don't mind if I ask more questions on the solution.

You are reading the file in f.read() which reads the whole file, and so the file descriptor moves forward, which means the text can't be read again when you do f.read() the next time.
If you need to search on the same text again, save the output of f.read(), and then do a regular expression search on it as below:
import re
f = open('C:/Users/Jyoti/Desktop/PythonPrograms/try.xml','r')
text = f.read()
opentag = re.search('<TEXT>',text)
begin = opentag.start()+6
print begin
closetag = re.search('</TEXT>',text)
end = closetag.start() - 1
print end

f.read() reads the whole file. So there's nothing left to read on the second f.read() call.
See https://docs.python.org/2/tutorial/inputoutput.html#methods-of-file-objects

First of all you have to know that f.read() after read file sets the pointer to the EOF so if you again use f.read() it gives you empty string ''. Secondly you should use r before string passed as a pattern of re.search function, which means raw, and automatically escapes special characters. So you have to do something like this:
import re
f = open('C:/Users/Jyoti/Desktop/PythonPrograms/try.xml','r')
data = f.read()
opentag = re.search(r'<TEXT>',data)
begin = opentag.start()+6
print begin
closetag = re.search(r'</TEXT>',data)
end = closetag.start() - 1
print end
gl & hf with Python :)