Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
149 views
in Technique[技术] by (71.8m points)

python - Removing a prefix from a string

Trying to strip the "0b1" from the left end of a binary number.

The following code results in stripping all of binary object. (not good)

>>> bbn = '0b1000101110100010111010001' #converted bin(2**24+**2^24/11)
>>> aan=bbn.lstrip("0b1")  #Try stripping all left-end junk at once.
>>> print aan    #oops all gone.
''

So I did the .lstrip() in two steps:

>>> bbn = '0b1000101110100010111010001' #    Same fraction expqansion
>>> aan=bbn.lstrip("0b")# Had done this before.
>>> print aan    #Extra "1" still there.
'1000101110100010111010001'
>>> aan=aan.lstrip("1")#  If at first you don't succeed...
>>> print aan    #YES!
'000101110100010111010001'

What's the deal?

Thanks again for solving this in one simple step. (see my previous question)

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

The strip family treat the arg as a set of characters to be removed. The default set is "all whitespace characters".

You want:

if strg.startswith("0b1"):
   strg = strg[3:]

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...