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Arcpy Calculate Field Stores a String in Scientific Notation

BrandonZaitz

I have an attribute field that is API well numbers and when I calculate a "TEXT" field using arcpy it converts those API numbers into scientific notation. However, when I calculate the field in Arcmap using the GUI it stores the full API number correctly. Has anyone else had this issue? How might i ensure that this doesn't happen?

I have tried both:

arcpy.CalculateField_management(shapefile,fieldname,"!{}!".format(inputfieldname),"PYTHON")

and:

arcpy.CalculateField_management(shapefile,fieldname,"str(!{}!)".format(inputfieldname),"PYTHON")

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DanPatterson_Retired

bare formatting can cause some issues depending on what is first passed to it. You can mitigate a bit by specifying how to treat numerics by prespecifying the size and decimals (even for integers)

a = 30015364700000

"{:<16.0f}".format(a)

'30015364700000 '

with a space to spare

BrandonZaitz

Ok, so i have narrowed it down to .format() causing the problem.

The code below DOES NOT give me scientific notation as a result.

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">CreateAPIText</SPAN><SPAN class="punctuation token">(</SPAN>shapefile<SPAN class="punctuation token">,</SPAN>inputfieldname<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<SPAN class="keyword token">import</SPAN> arcpy
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;fieldname <SPAN class="operator token">=</SPAN> <SPAN class="string token">"API_Text"</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<SPAN class="comment token">#Add field for string API</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;arcpy<SPAN class="punctuation token">.</SPAN>AddField_management<SPAN class="punctuation token">(</SPAN>shapefile<SPAN class="punctuation token">,</SPAN>fieldname<SPAN class="punctuation token">,</SPAN><SPAN class="string token">"TEXT"</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">14</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<SPAN class="comment token">#Calculate value for API TEXT field</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;arcpy<SPAN class="punctuation token">.</SPAN>CalculateField_management<SPAN class="punctuation token">(</SPAN>shapefile<SPAN class="punctuation token">,</SPAN>fieldname<SPAN class="punctuation token">,</SPAN><SPAN class="string token">"!API!"</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">"PYTHON"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">""</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

The code below WAS outputing the fields in scientific notation.

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">CreateAPIText</SPAN><SPAN class="punctuation token">(</SPAN>shapefile<SPAN class="punctuation token">,</SPAN>inputfieldname<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<SPAN class="keyword token">import</SPAN> arcpy
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;fieldname <SPAN class="operator token">=</SPAN> <SPAN class="string token">"API_Text"</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<SPAN class="comment token">#Add field for string API</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;arcpy<SPAN class="punctuation token">.</SPAN>AddField_management<SPAN class="punctuation token">(</SPAN>shapefile<SPAN class="punctuation token">,</SPAN>fieldname<SPAN class="punctuation token">,</SPAN><SPAN class="string token">"TEXT"</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="number token">14</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<SPAN class="comment token">#Calculate value for API TEXT field</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;arcpy<SPAN class="punctuation token">.</SPAN>CalculateField_management<SPAN class="punctuation token">(</SPAN>shapefile<SPAN class="punctuation token">,</SPAN>fieldname<SPAN class="punctuation token">,</SPAN><SPAN class="string token">"!{}!"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>inputfieldname<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">"PYTHON"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">""</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

However, i can not seem to replicate the problem this morning.

If if happens again I may be back but thanks to everyone for the input.

bixb0012

I just tested your code using the interactive Python window in ArcCatalog 10.6.1, and the results are as expected for both a feature class table and DBF table:

BrandonZaitz

Below is the entire function:

<SPAN class="keyword token">def</SPAN> <SPAN class="token function">CreateAPIText</SPAN><SPAN class="punctuation token">(</SPAN>shapefile<SPAN class="punctuation token">,</SPAN>inputfieldname<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<SPAN class="keyword token">import</SPAN> arcpy
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;fieldname <SPAN class="operator token">=</SPAN> <SPAN class="string token">"API_Text"</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<SPAN class="comment token">#Add field for string API</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;arcpy<SPAN class="punctuation token">.</SPAN>AddField_management<SPAN class="punctuation token">(</SPAN>shapefile<SPAN class="punctuation token">,</SPAN>fieldname<SPAN class="punctuation token">,</SPAN><SPAN class="string token">"TEXT"</SPAN><SPAN class="punctuation token">)</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<SPAN class="comment token">#Calculate value for API TEXT field</SPAN>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;arcpy<SPAN class="punctuation token">.</SPAN>CalculateField_management<SPAN class="punctuation token">(</SPAN>shapefile<SPAN class="punctuation token">,</SPAN>fieldname<SPAN class="punctuation token">,</SPAN><SPAN class="string token">"!{}!"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>inputfieldname<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">,</SPAN><SPAN class="string token">"PYTHON"</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

BrandonZaitz

The field i am calculating from is a Double.

BrandonZaitz

Arc Version is 10.6.0.8321

BrandonZaitz

The field width is 255 and is a string. The code you provided only works if i change the 'f' to 's'.

bixb0012

I had to store the number as double and then use the code to covert to string. As you point out, the number can't be stored in long.

DanPatterson_Retired

If 'Long' in ArcMap or ArcGIS Pro is 32bit integers, then the maximum length of a field and the maximum value is dictated by the integer type. From other c based number types, these are as follows

32bit integers 10 characters with the maximum as 2,147,483,647

Arc* stores long as -2,147,483,648 to 2,147,483,647

64bit integers 19 characters with the maximum as 9,223,372,036,854,775,807

your number is 14 characters long as an integer, 30,015,364,700,000 .... beyond the 32bit long maximum

So if your key has to be that long, then you had better use a text field since

np<SPAN class="punctuation token">.</SPAN>iinfo<SPAN class="punctuation token">(</SPAN>np<SPAN class="punctuation token">.</SPAN>int32<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">.</SPAN>max
<SPAN class="number token">2147483647</SPAN>

np<SPAN class="punctuation token">.</SPAN>iinfo<SPAN class="punctuation token">(</SPAN>np<SPAN class="punctuation token">.</SPAN>int64<SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">.</SPAN>max
<SPAN class="number token">9223372036854775807</SPAN>‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Now if we convert that integer you have to float32 (32 bit float) we get

np.asarray([30015364700000]).astype(np.float32)
array([3.0015364e+13], dtype=float32)

np.asscalar(a) # not good
30015364268032.0

b =np.asarray([30015364700000]).astype(np.float64)

array([3.00153647e+13])

np.asscalar(b) # better
30015364700000.0

bixb0012

I just tried using your code with both a feature class and shape file, and it works correctly for me, i.e, it doesn't use scientific notation. What version of ArcMap are you using?

DanPatterson_Retired

The field width is > 14 characters and defined as Text for the output field?

The only other thing I can think of is explicitly formatting the output string

a <SPAN class="operator token">=</SPAN> <SPAN class="number token">30015364700000</SPAN>

<SPAN class="string token">"{:<14.0f}"</SPAN><SPAN class="punctuation token">.</SPAN>format<SPAN class="punctuation token">(</SPAN>a<SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

BrandonZaitz

For instance, "30015364700000" will store as "3.00153647e+13".

bixb0012

Can you give an example number?

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