Maybe I have trival issue but I can't find solution.
I use Raspberry Pi to read value from serial port. Input from serial looks like " b'1\r\n' ".
In this input I need only the number. I tried this code:
data = str(data)
data = data[2:7]
data = data.replace("\r\n","")
print(data)
Output of this code is : "1\r\n". I can't get rid of this part of string, replace function just doesn't work and I don't know why.
you have bytes you can use the decode method of bytes to get back a string. you can then use rstrip method of str to remove the trailing new line chars.
data = b'1\r\n'
print(data)
data = data.decode(('utf-8;')).rstrip()
print(data)
OUTPUT
b'1\r\n'
1
Related
Using python 3.6. I have a bytes array that is coming over a socket (a FIX message) that contains hex character 1, start of header, as a delimiter. The raw bytes look like
b'8=FIX.4.4\x019=65\x0135=0\x0152=20220809-21:37:06.893\x0149=TRADEWEB\x0156=ABFIXREPO\x01347=UTF-8\x0110=045\x01'
I want to store this bytes array to a file for logging. I have seen FIX messages where this delimiter is converted to ^A control character. The final string I would like to have is -
8=FIX.4.4^A9=65^A35=0^A52=20220809-21:37:06.893^A49=TRADEWEB^A56=ABFIXREPO^A347=UTF-8^A10=045^A
I have tried various different ways to achieve this but could not, for example, tried repr(bytes) and (ord(b) in bytes).
Any pointers are highly appreciated.
Thanks.
One way I can think of doing this is by splitting the original decoded byte array , and insert control character using a loop.
data = b'8=FIX.4.4\x019=65\x0135=0\x0152=20220809-21:37:06.893\x0149=TRADEWEB\x0156=ABFIXREPO\x01347=UTF-8\x0110=045\x01'
data = data.decode().split("\x01")
print(data)
ctl_char = "^A"
string =""
for i in data:
string+=i
string+=ctl_char
print(string)
Please note there can be a better way of doing it.
I have a .tgz file that was formatted as shell code, it looks like this (Hex):
"\x1F\x8B\x08\x00\x44\x7A\x91\x4F\x00\x03\xED\x59\xED\x72.."
It was generated this way (python3):
import os
def main():
dump_src = "MyPlugin.tgz"
fc = ""
try:
with open(dump_src, 'rb') as fd:
fcr = fd.read()
for byte in bytearray(fcr):
fc += "\\x{:02x}".format(byte)
except:
fcr = dump_src
for byte in bytearray(fcr):
fc += "\\x{:02x}".format(byte)
print(fc)
# failed attempt:
fcback = bytes(int(fc[i+2:i+4], 16) for i in range(0, len(fc), 4))
print (fcback)
if __name__ == "__main__":
main()
How can I convert this back to the original tgz archive?
Edit: failed attempt in the last section outputs this:
b'\x8b\x00\x10]\x03\x93o0\x85%\xe2!\xa4H\xf1Fi\xa7\x15\xf61&\x13N\xd9[\xfag\x11V\x97\xd3\xfb%\xf7\xe3\\\xae\xc2\xff\xa4>\xaf\x11\xcc\x93\xf1\x0c\x93\xa4\x1b\xefxj\xc3?\xf9\xc1\xe8\xd1\xd9\x01\x97qB"\x1a\x08\x9cO\x7f\xe9\x19\xe3\x9c\x05\xf2\x04a\xaa\x00A,\x15"RN-\xb6\x18K\x85\xa1\x11\x83\xac/\xffR\x8a\xa19\xde\x10\x0b\x08\x85\x93\xfc]\x8a^\xd2-T\x92\x9a\xcc-W\xc7|\xba\x9c\xb3\xa6V0V H1\x98\xde\x03#\x14\'\n 1Y\xf7R\x14\xe2#\xbe*:\xe0\xc8\xbb\xc9\x0bo\x8bm\xed.\xfd\xae\xef\x9fT&\xa1\xf4\xcf\xa7F\xf4\xef\xbb"8"\xb5\xab,\x9c\xbb\xfc3\x8b\xf5\x88\xf4A\x0ek%5eO\xf4:f\x0b\xd6\x1bi\xb6\xf3\xbf\xf7\xf9\xad\xb5[\xdba7\xb8\xf9\xcd\xba\xdd,;c\x0b\xaaT"\xd4\x96\x17\xda\x07\x87& \xceH\xd6\xbf\xd2\xeb\xb4\xaf\xbd\xc2\xee\xfc\'3zU\x17>\xde\x06u\xe3G\x7f\x1e\xf3\xdf\xb6\x04\x10A\x04\x10A\x04\x10A\x04\x10A\xff\x9f\xab\xe8(\x00'
And when I output it to a file (e.g. via python3 main.py > MyFile.tgz) the file is corrupted.
Since you know the format of the data (each byte is encoded as a string of 4 characters in the format "\xAB") it's easy to revert the conversion and get the original bytes again. It'll only take one line of Python code:
data = bytes(int(fc[i+2:i+4], 16) for i in range(0, len(fc), 4))
This uses:
range(start, stop, step) with step 4 to iterate in groups of 4 characters through your string
slicing to get each group of 2 hexadecimal digits
int(x, base) to convert the hexadecimal string to an integer
a generator expression to immediately pass the converted elements to:
bytes() to create a bytes object with the data
The variable data is now of type bytes and you could directly write it to a file (to decompress with an external zip program), or pass it to zlib.decompress() (to further process it in Python).
UPDATE (follow-up on the comments and updated question):
Firstly, I have tested the above code and it does result in the same bytes as the input. Are you really sure that the example output in your question is the actual result of the code in your question? Please try to be careful when copying code and/or output. A few remarks:
Your code is not properly formatted, so I cannot run it without making modifications. And when I have made modifications to the code, I might run different code than you do, yielding different results. So next time please copy-paste your exact (working, tested) code without modifications.
The format string in your code uses lowercase hexadecimal format, and your first example output uses uppercase. So that output cannot be from this code.
I don't have access to your file "MyPlugin.tgz", but when I test your code with another .tgz file (after fixing the IndentationErrors), my output is correct. It starts with \x1f\x8b as expected (this is the magic number in the gzip header). I can't explain why your output is different...
Secondly, it seems like you don't fully understand how bytes and string representations work. When you write print(fcback), a string representation of the Python object fcback (in this case a bytes object) is printed. The string representation of a bytes object is not the same as the binary data! When printing a bytes object, each byte that corresponds to a printable ASCII character is replaced by that character, other bytes are escaped (similar to the formatted string that your code generates). Also, it starts with b' and ends with '.
You cannot print binary data to your terminal and then pipe the output to a file. This will result in a different file. The correct way to write the data to a file is using file.write(data) in your Python code.
Here's a fully working example:
def binary_to_text(data):
"""Convert a bytes object to a formatted text string."""
text = ""
for byte in data:
text += "\\x{:02x}".format(byte)
return text
def text_to_binary(text):
"""Convert a formatted text string to a bytes object."""
return bytes(int(text[i+2:i+4], 16) for i in range(0, len(text), 4))
def main():
# Read the binary data from input file:
with open('MyPlugin.tgz', 'rb') as input_file:
input_data = input_file.read()
# Convert binary to text (based on your original code):
text = binary_to_text(input_data)
print(text[0:100])
# Convert the text back to binary:
output_data = text_to_binary(text)
print(output_data[0:100])
# Write the binary data back to a file:
with open('MyPlugin-restored.tgz', 'wb') as output_file:
output_file.write(output_data)
if __name__ == '__main__':
main()
Note that I only print the first 100 elements to keep the output short. Also notice that the second print-statement prints a much longer text. This is because the first print gets 100 characters (which are printed "as is"), while the second print gets 100 bytes (of which most bytes are escaped, causing the output to be longer).
I am working on a project in which i am getting data from an arduino over serial communication. So i open a ser = serial.Serial('/dev/ttyACM1', 9600) and everything is working fine. The thing is that i wrote this code to check when the data i get is 0 but i can't get it work.
while True:
try :
a = ser.readline()
# i do that because the input stream is smthg like b' 16.894548\r\n'
data = a.decode('utf-8')
print(a is str(str(0).encode('utf-8').decode('utf-8', "strict")))
I have tried many things, like getting the sizeof, encode and decode, making everything a str after decoding. But still no luck.
Any ideas?
Use == to compare strings, not is
Note that you have new line characters in the end. '0' != '0/r/n'.
Try
a = ser.readline()
print(a.decode().strip() == '0')
I try to use google polyline to decode the data. My data looks like
'yrwFpjpbMbDxB|BxAtBxAjFhDrFnDFHlBnAtBtAzBvAvFrDl#\\MfFNHo#~CtF|BXLn#aDp#}Cp#mCfAuD\{AlKmg##]L{#pAoGNup#bCoL#gBf#eC^gBb#cBjD{P\oBVyAFgA?cAs#_QK}#Q_AYcAa#cA]i#m#w#w#q#a#WuCyAcAk#}#o#aA{#}#}#aBuBG[m#m#oEuFcAwAmB}CeDaG_FcJqAeCm#oAKe#Yu#c#aBa#cB[eBEa#fCeBlCYzGq#ZzG'
If I put this string into the code
polyline.decode('yrwFpjpbMbDxB|BxAtBxAjFhDrFnDFHlBnAtBtAzBvAvFrDl#\\MfFNHo#~CtF|BXLn#aDp#}Cp#mCfAuD\{AlKmg##]L{#pAoGNup#bCoL#gBf#eC^gBb#cBjD{P\oBVyAFgA?cAs#_QK}#Q_AYcAa#cA]i#m#w#w#q#a#WuCyAcAk#}#o#aA{#}#}#aBuBG[m#m#oEuFcAwAmB}CeDaG_FcJqAeCm#oAKe#Yu#c#aBa#cB[eBEa#fCeBlCYzGq#ZzG'), it gives me the data.
However, if I run the program and save the string into a list, like code[],
and run the code
polyline.decode(code[0]), the error will say:
IndexError: string index out of range
I tried many times and cannot figure the problem.Can anybody tell me what I'm doing wrong? Thanks in advance!
It might be related to the escape characters in your string.
I a similar issue when copy/pasting a an encoded string from a web call into a python script as a raw string:
encoded_string = r"<pasted string>"
l = polyline.decode(encoded_string)
>>
>> .. IndexError: string index out of range
When making it a normal string (removing the 'r' qulification) it worked
encoded_string = "<pasted string>"
l = polyline.decode(encoded_string)
I am trying to extract the main article from a web page. I can accomplish the main text extraction using Python's readability module. However the text I get back often contains several 
 strings (there is a ; at the end of this string but this editor won't allow the full string to be entered (strange!)). I have tried using the python replace function, I have also tried using regular expression's replace function, I have also tried using the unicode encode and decode functions. None of these approaches have worked. For the replace and Regular Expression approaches I just get back my original text with the 
 strings still present and with the unicode encode decode approach I get back the error message:
UnicodeEncodeError: 'ascii' codec can't encode character u'\xa9' in position 2099: ordinal not in range(128)
Here is the code I am using that takes the initial URL and using readability extracts the main article. I have left in all my commented out code that corresponds to the different approaches I have tried to remove the
string. It appears as though 
 is interpreted to be u'\xa9'.
from readability.readability import Document
def find_main_article_text_2():
#url = 'http://finance.yahoo.com/news/questcor-pharmaceuticals-closes-transaction-acquire-130000695.html'
url = "http://us.rd.yahoo.com/finance/industry/news/latestnews/*http://us.rd.yahoo.com/finance/external/cbsm/SIG=11iiumket/*http://www.marketwatch.com/News/Story/Story.aspx?guid=4D9D3170-CE63-4570-B95B-9B16ABD0391C&siteid=yhoof2"
html = urllib.urlopen(url).read()
readable_article = Document(html).summary()
readable_title = Document(html).short_title()
#readable_article.replace("u'\xa9'"," ")
#print re.sub("
",'',readable_article)
#unicodedata.normalize('NFKD', readable_article).encode('ascii','ignore')
print readable_article
#print readable_article.decode('latin9').encode('utf8'),
print "There are " ,readable_article.count("
"),"
's"
#print readable_article.encode( sys.stdout.encoding , '' )
#sent_tokenizer = nltk.data.load('tokenizers/punkt/english.pickle')
#sents = sent_tokenizer.tokenize(readable_article)
#new_sents = []
#for sent in sents:
# unicode_sent = sent.decode('utf-8')
# s1 = unicode_sent.encode('ascii', 'ignore')
#s2 = s1.replace("\n","")
# new_sents.append(s1)
#print new_sents
# u'\xa9'
I have a URL that I have been testing the code with included inside the def. If anybody has any ideas on how to remove this 
 I would appreciate the help. Thanks, George