Ethereum generating genesis Python Syntax

Question

I tried to generate the genesis file but get this error:

C:\Python34>python mk_genesis_block.py --extradata 0x11bbe8db4e347b4e8c937c1c837
0e4b5ed33adb3db69cbdb7a38e1e50b1b82fa > genesis_block.json
  File "mk_genesis_block.py", line 293
    print json.dumps(evaluate(), indent=4)
             ^
SyntaxError: invalid syntax

Edit: Here is the surrounding lines:

if __name__ == '__main__':
    print json.dumps(evaluate(), indent=4)

Then it's EOF. The whole file can be viewed here Since the offending line seems to be only output, I commented it and got another error:

C:\Python34>python -tt mk_genesis_block.py --extradata 0x11bbe8db4e347b4e8c937c1
c8370e4b5ed33adb3db69cbdb7a38e1e50b1b82fa > genesis_block.json
Traceback (most recent call last):
  File "mk_genesis_block.py", line 124, in <module>
    EXTRADATA = (d[2:] if d[:2] == '0x' else d).decode('hex')
AttributeError: 'str' object has no attribute 'decode'

which in conjunction with the other error makes me wonder whether a string instead of a json object is being operated on? Here is the whole arg parsing part:

# Grab the extra data command line argument
if '--extradata' in sys.argv:
    d = (sys.argv+[None])[sys.argv.index('--extradata') + 1]
    EXTRADATA = (d[2:] if d[:2] == '0x' else d).decode('hex')
else:
    EXTRADATA = ''

I also made a test file importing the json package, dumps and decode methods work.

Omkar · Answer 1 · Oct 10, 2018

print in python3 is a method not a statement print( "text" ) ... also I believe str.decode was remove in python3 ... instead use codecs.decode(my_str,encoding)