5.7.1 Table of exceptions names

This table gives a list of sympy exceptions generated that could indicate an internal bug in Sympy dsolve.

TableĀ 5.163: List of Sympy dsolve exceptions generated

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Exception

1

TypeError : bad operand type for unary -: list 
 

2

RecursionError : maximum recursion depth exceeded 
 

3

TypeError : cannot determine truth value of Relational 
 

4

TypeError : NoneType object is not subscriptable 
 

5

ValueError : Expected Expr or iterable but got None 
 

6

ZeroDivisionError : polynomial division 
 

7

TypeError : property object is not iterable 
 

8

TypeError : < not supported between instances of NoneType and Zero 
 

9

IndexError : list index out of range 
 

10

IndexError : Index out of range: a[1] 
 

11

AssertionError : [False] 
 

12

KeyError : _y 
 

13

ValueError : x + sin(y(x))**2*tan(y(x)) is not a solvable differential equation in y(x) 
 

14

KeyError : ordered_hints 
 

15

TypeError : < not supported between instances of NoneType and y 
 

16

NonlinearError : nonlinear term: sqrt(-a*b) 
 

17

Series solution not supported for ode of order > 2 
 

18

TypeError : argument of type Mul is not iterable 
 

19

ValueError : Rational Solution doesnt exist 
 

20

TypeError : argument of type NegativeOne is not iterable 
 

21

IndexError : tuple index out of range 
 

22

PolynomialDivisionFailed : couldnt reduce degree in a polynomial division algorithm when dividing [[], [], [], []] by [[ANP([mpq(1,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ)], [ANP([mpq(-1,1), mpq(-1,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ)]]. This can happen when its not possible to detect zero in the coefficient domain. The domain of computation is QQ<I>. Zero detection is guaranteed in this coefficient domain. This may indicate a bug in SymPy or the domain is user defined and doesnt implement zero detection properly. 
 

23

TypeError : invalid input: 1 - (-21 + 4*sqrt(5))/(-1 + 2*sqrt(5)) 
 

24

TypeError : Invalid NaN comparison 
 

25

PolynomialDivisionFailed : couldnt reduce degree in a polynomial division algorithm when dividing [[], []] by [[ANP([mpq(1,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ), ANP([mpq(-2,1), mpq(0,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ), ANP([mpq(-2,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ)]]. This can happen when its not possible to detect zero in the coefficient domain. The domain of computation is QQ<I>. Zero detection is guaranteed in this coefficient domain. This may indicate a bug in SymPy or the domain is user defined and doesnt implement zero detection properly. 
 

26

TypeError : Symbol object cannot be interpreted as an integer 
 

27

TypeError : Mul object cannot be interpreted as an integer 
 

28

TypeError : Add object cannot be interpreted as an integer 
 

29

TypeError : invalid input: 1 - v 
 

30

TypeError : invalid input: 1 - a 
 

31

TypeError : invalid input: 1 - b/a 
 

32

TypeError : invalid input: 2*a + b 
 

33

NotInvertible : zero divisor 
 

34

ODEMatchError : nth_linear_constant_coeff_undetermined_coefficients solver cannot solve: nan 
 

35

KeyError : Derivative(y(t), (t, 2)) 
 

36

KeyError : Derivative(y(t), t) 
 

37

ValueError : substitution cannot create dummy dependencies 
 

38

KeyError : F2_ 
 

39

AttributeError : list object has no attribute func 
 

40

PolynomialDivisionFailed : couldnt reduce degree in a polynomial division algorithm when dividing [[], [ANP([mpq(-1,1), mpq(0,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ), ANP([mpq(1,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ)]] by [[ANP([mpq(1,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ)]]. This can happen when its not possible to detect zero in the coefficient domain. The domain of computation is QQ<I>. Zero detection is guaranteed in this coefficient domain. This may indicate a bug in SymPy or the domain is user defined and doesnt implement zero detection properly. 
 

41

TypeError : argument of type Pow is not iterable 
 

42

HeuristicGCDFailed : no luck 
 

43

TypeError : invalid input: 1 - n 
 

44

TypeError : invalid input: 2*a + 1 
 

45

TypeError : Invalid comparison of non-real 1 + sqrt(7)*I 
 

46

TypeError : exp takes exactly 1 argument (2 given) 
 

47

PolynomialDivisionFailed : couldnt reduce degree in a polynomial division algorithm when dividing [[], [ANP([mpq(-1,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ), ANP([mpq(4,1), mpq(0,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ), ANP([mpq(6,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ), ANP([mpq(-4,1), mpq(0,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ), ANP([], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ)]] by [[ANP([mpq(1,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ), ANP([mpq(-2,1), mpq(0,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ), ANP([mpq(-2,1)], [mpq(1,1), mpq(0,1), mpq(1,1)], QQ)]]. This can happen when its not possible to detect zero in the coefficient domain. The domain of computation is QQ<I>. Zero detection is guaranteed in this coefficient domain. This may indicate a bug in SymPy or the domain is user defined and doesnt implement zero detection properly. 
 

48

ValueError : function with different numbers of args 
 

49

OverflowError : mpz too large to convert to float 
 

50

PolynomialError : non-commutative expressions are not supported 
 

51

ValueError : It solves only those systems of equations whose orders are equal 
 

52

TypeError : invalid input: 1 - 2*p 
 

53

TypeError : < not supported between instances of NoneType and x 
 

54

TypeError : invalid input: 2*n + 1