Convert base-2 binary number string to int

Question

I d simply like to convert a base-2 binary number string into an int  something like this    gt  gt  gt   11111111  fromBinaryToInt   255   Is there a way to do this in Python

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For the record to go back and forth in basic python3  a   10 bin a     0b1010   int bin a   2    10 eval bin a     10

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Using int with base is the right way to go  I used to do this before I found int takes base also  It is basically a reduce applied on a list comprehension of the primitive way of converting binary to decimal   e g  110   2  0   0   2    1   1   2    2   1   add   lambda x y   x   y reduce add   int x    2    y for x  y in zip list binstr   range len binstr  - 1  -1  -1

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You use the built-in int function  and pass it the base of the input number  i e  2 for a binary number    gt  gt  gt  int  11111111   2  255   Here is documentation for python2  and for python3

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Just type 0b11111111 in python interactive interface    gt  gt  gt  0b11111111     255

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Another way to do this is by using the bitstring module   gt  gt  gt  from bitstring import BitArray  gt  gt  gt  b   BitArray bin  11111111    gt  gt  gt  b uint 255  Note that the unsigned integer is different from the signed integer   gt  gt  gt  b int -1  The bitstring module isn t a requirement  but it has lots of performant methods for turning input into and from bits into other forms  as well as manipulating them

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If you are using python3 6 or later you can use f-string to do the   conversion    Binary to decimal    gt  gt  gt  print f  0b1011010  0    90   gt  gt  gt  bin 2 decimal   int f  0b1011010  0     gt  gt  gt  bin 2 decimal 90   binary to octal hexa and etc    gt  gt  gt  f  0b1011010  o    0o132     octal   gt  gt  gt  f  0b1011010  x    0x5a      hexadecimal   gt  gt  gt  f  0b1011010  0    90        decimal   Pay attention to 2 piece of information separated by colon    In this way  you can convert between  binary  octal  hexadecimal  decimal  to  binary  octal  hexadecimal  decimal  by changing right side of colon       b - gt  converts to binary   o - gt  converts to octal   x - gt  converts to hexadecimal    0 - gt  converts to decimal as above example   Try changing left side of colon to have octal hexadecimal decimal

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If you wanna know what is happening behind the scene  then here you go     class Binary    def   init   self  binNumber       self  binNumber   binNumber     self  binNumber   self  binNumber   -1      self  binNumber   list self  binNumber      self  x    1      self  count   1     self  change   2     self  amount   0     print self  ToNumber self  binNumber   def  ToNumber self  number       self  number   number     for i in range  1  len  self  number            self  total   self  count   self  change         self  count   self  total         self  x append self  count      self  deep   zip self  number  self  x      for self  k  self  v in self  deep          if self  k     1               self  amount    self  v     return self  amount mo   Binary  101111110

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A recursive Python implementation   def int2bin n       return int2bin n  gt  gt  1     n  amp  1  if n  gt  1 else  1

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For large matrix  10  5 rows and up  it is better to use a vectorized matmult  Pass in all rows and cols in one shot   It is extremely fast  There is no looping in python here  I originally designed it for converting many binary columns like 0 1 for like 10 different genre columns in MovieLens into a single integer for each example row   def BitsToIntAFast bits     m n   bits shape   a   2  np arange n    -1     -1 reverses array of powers of 2 of same length as bits   return bits   a

[python] Convert base-2 binary number string to int

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