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Why did Sympy cut polynomial terms with low coefficients?

I am trying to convert an expression containing terms with different degrees of a symbolic variable z_sinto a polynomial in python using sympy.Poly()to then extract the coefficients using .coeffs().

Expression i has a high order polynomial with independent symbolic variable z_s. For some reason, when I convert an expression to a polynomial using sympy.Poly (), it seems to chop off members with small coefficients. Below is my function, and I included a line where I redefined it as a symbolic polynomial:

f = -1.29096669270427e-61*z_s**33 + 6.24438995041203e-59*z_s**32 - 6.41125090009095e-57*z_s**31 - 8.30852813320818e-55*z_s**30 + 5.84175807723288e-53*z_s**29 + 1.88577332997761e-50*z_s**28 + 9.46504910106607e-49*z_s**27 - 2.28903644846359e-46*z_s**26 - 4.63321594171589e-44*z_s**25 - 1.78254194888339e-42*z_s**24 + 6.43406800910469e-40*z_s**23 + 1.20425521347205e-37*z_s**22 + 3.4116753522246e-36*z_s**21 - 1.92084369416715e-33*z_s**20 - 3.04107684362554e-31*z_s**19 + 2.89289551256439e-30*z_s**18 + 6.38382842182985e-27*z_s**17 + 5.46438700248253e-25*z_s**16 - 8.50501280745176e-23*z_s**15 - 1.6344595302306e-20*z_s**14 + 1.07764488797684e-18*z_s**13 + 3.47026242660686e-16*z_s**12 - 2.93966702403133e-14*z_s**11 - 5.25394006214533e-12*z_s**10 + 1.21642330162702e-9*z_s**9 - 1.16577645027166e-7*z_s**8 + 6.82117624588787e-6*z_s**7 - 0.000267513120031891*z_s**6 + 0.00723589681411793*z_s**5 - 0.134846078975788*z_s**4 + 1.69035817278476*z_s**3 - 13.5277365002646*z_s**2 + 62.3459673862853*z_s - 76.5029927727737
sympy.Poly(f,z_s)

This returns:

Poly(-2.93966702403133e-14*z_s**11 - 5.25394006214533e-12*z_s**10 + 1.21642330162702e-9*z_s**9 - 1.16577645027166e-7*z_s**8 + 6.82117624588787e-6*z_s**7 - 0.000267513120031891*z_s**6 + 0.00723589681411793*z_s**5 - 0.134846078975788*z_s**4 + 1.69035817278476*z_s**3 - 13.5277365002646*z_s**2 + 62.3459673862853*z_s - 76.5029927727737, z_s, domain='RR')

As you can see, the first few terms have been deduced.

At first I thought it cut off my high-order terms because there was some built-in cut-off for high-order polynomials, but I could not find it in any documentation. Then I discovered that the terms that are being truncated seem to be truncated due to the low value of the coefficient (I believe that simplex or python believe that this term is void because its coefficient is so close to zero). You can see in my function that the first term has a coefficient of approximately -1.3e-61. I tested this theory using a simple example of a 2-thermal polynomial with degree 1, which has a "small" term cut off:
h = 10e-27*z_s + 1
sympy.Poly(h,z_s)

(EDIT: + 1should have been in a function h, I just fixed it so that it reads correctly. This does not change the result.) This returns:

Poly(1.0, z_s, domain='RR')

, , 10e-27, , (1.0).

SymPy ( ). , , (. ): , PREVENT PREVENT .

python/sympy, , ?

, , , sympy.Poly() .coeffs()?

+4
1

, sympy , . , domain='QQ', float.

:

import sympy
z_s = symbols('z_s')
f = -1.29096669270427e-61*z_s**33 + 6.24438995041203e-59*z_s**32 - 6.41125090009095e-57*z_s**31 - 8.30852813320818e-55*z_s**30 + 5.84175807723288e-53*z_s**29 + 1.88577332997761e-50*z_s**28 + 9.46504910106607e-49*z_s**27 - 2.28903644846359e-46*z_s**26 - 4.63321594171589e-44*z_s**25 - 1.78254194888339e-42*z_s**24 + 6.43406800910469e-40*z_s**23 + 1.20425521347205e-37*z_s**22 + 3.4116753522246e-36*z_s**21 - 1.92084369416715e-33*z_s**20 - 3.04107684362554e-31*z_s**19 + 2.89289551256439e-30*z_s**18 + 6.38382842182985e-27*z_s**17 + 5.46438700248253e-25*z_s**16 - 8.50501280745176e-23*z_s**15 - 1.6344595302306e-20*z_s**14 + 1.07764488797684e-18*z_s**13 + 3.47026242660686e-16*z_s**12 - 2.93966702403133e-14*z_s**11 - 5.25394006214533e-12*z_s**10 + 1.21642330162702e-9*z_s**9 - 1.16577645027166e-7*z_s**8 + 6.82117624588787e-6*z_s**7 - 0.000267513120031891*z_s**6 + 0.00723589681411793*z_s**5 - 0.134846078975788*z_s**4 + 1.69035817278476*z_s**3 - 13.5277365002646*z_s**2 + 62.3459673862853*z_s - 76.5029927727737
[sympy.N(c) for c in sympy.poly(f,z_s,domain='QQ').coeffs()] 


[-1.29096669270427e-61, 6.24438995041203e-59, -6.41125090009095e-57, -8.30852813320818e-55, 5.84175807723288e-53, 1.88577332997761e-50, 9.46504910106607e-49, -2.28903644846359e-46, -4.63321594171589e-44, -1.78254194888339e-42, 6.43406800910469e-40, 1.20425521347205e-37, 3.41167535222460e-36, -1.92084369416715e-33, -3.04107684362554e-31, 2.89289551256439e-30, 6.38382842182985e-27, 5.46438700248253e-25, -8.50501280745176e-23, -1.63445953023060e-20, 1.07764488797684e-18, 3.47026242660686e-16, -2.93966702403133e-14, -5.25394006214533e-12, 1.21642330162702e-9, -1.16577645027166e-7, 6.82117624588787e-6, -0.000267513120031891, 0.00723589681411793, -0.134846078975788, 1.69035817278476, -13.5277365002646, 62.3459673862853, -76.5029927727737]
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