64

I am trying to run the code presented on the second page:

http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-00-introduction-to-computer-science-and-programming-fall-2008/video-lectures/lecture-20/lec20.pdf

At the bottom of the code you have to add these lines:

simFlips(100,100)

show()

Here is the error that I get when I run it on ubuntu:

Traceback (most recent call last):
  File "coin.py", line 36, in <module>
    simFlips(100,100)
  File "coin.py", line 16, in simFlips
    diffs.append(abs(heads - tails))
AttributeError: 'numpy.ndarray' object has no attribute 'append'

Please tell me what I'm doing wrong that gives me the last error. Thanks in advance!

vahshi
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    For some reason your `diffs` variable is a numpy ndarray. Are you sure you left the line that says `diffs = []`? This sets diffs to be an empty python list, which you can call `append` on. – John Lyon Dec 07 '11 at 02:06
  • Works for me as written. – DSM Dec 07 '11 at 02:09
  • Yes I did, I just took the code from the pdf added the two lines at the bottom and started to get this error. – vahshi Dec 07 '11 at 02:20
  • DSM, how did you execute the code. On ubuntu or a different platform? – vahshi Dec 07 '11 at 02:21

3 Answers3

56

Use numpy.concatenate(list1 , list2) or numpy.append() Look into the thread at Append a NumPy array to a NumPy array.

Community
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Arpita Biswas
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0

I got this error after change a loop in my program, let`s see:

for ...
  for ... 
     x_batch.append(one_hot(int_word, vocab_size))
     y_batch.append(one_hot(int_nb, vocab_size, value))
  ...
  ...
  if ...
        x_batch = np.asarray(x_batch)
        y_batch = np.asarray(y_batch)
...

In fact, I was reusing the variable and forgot to reset them inside the external loop, like the comment of John Lyon:

for ...
  x_batch = []
  y_batch = []
  for ... 
     x_batch.append(one_hot(int_word, vocab_size))
     y_batch.append(one_hot(int_nb, vocab_size, value))
  ...
  ...
  if ...
        x_batch = np.asarray(x_batch)
        y_batch = np.asarray(y_batch)
...

Then, check if you are using np.asarray() or something like that.

Eduardo Freitas
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0

You will have to use numpy function to append numpy arrays. Append will workk only for ordinary lists not numpy arrays.

Zamal Ali
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  • Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer). – Community Oct 30 '21 at 03:38