[FIXED] Trouble with iteratively creating a dictionary

Issue

I am playing with python just to learn. I have a dictionary

chrom_freq_0

{'A': 27.5,
 'A+': 29.14,
 'B': 30.87,
 'C': 16.35,
 'C+': 17.32,
 'D': 18.35,
 'D+': 19.45,
 'E': 20.6,
 'F': 21.83,
 'F+': 23.12,
 'G': 24.5,
 'G+': 25.96}

that I want to contain in another dictionary as several modified versions of itself (as well as an original version of itself) but I can't figure out how to iterate properly. It is only including the last item in each version of the modified dictionary dictionary.

This is my code

Chrom_Freq = {0 : chrom_frq_0}

for i in range (1, 9):
    for note, freq in chrom_freq_0.iteritems():
        Chrom_Freq[i] = {note : freq*(2**i)}

I get this:

Chrom_Freq

--->

{0: {'A': 27.5,
  'A+': 29.14,
  'B': 30.87,
  'C': 16.35,
  'C+': 17.32,
  'D': 18.35,
  'D+': 19.45,
  'E': 20.6,
  'F': 21.83,
  'F+': 23.12,
  'G': 24.5,
  'G+': 25.96},
 1: {'G+': 51.92},
 2: {'G+': 103.84},
 3: {'G+': 207.68},
 4: {'G+': 415.36},
 5: {'G+': 830.72},
 6: {'G+': 1661.44},
 7: {'G+': 3322.88},
 8: {'G+': 6645.76}}

Solution

Each assignment to Chrom_Freq[i] replaces the value from the previous assignment.

In order to accumulate the contents you need to update the existing one if the key exists:

if i in Chrom_Freq:
     Chrom_Freq[i].update({note : freq*(2**i)})
else:
     Chrom_Freq[i] = {note : freq*(2**i)}

Answered By - Alain T.