为什么print(eval( repr (Instance)调用str函数而不是repr函数？

Question

在下面的代码块中，为什么print(new)语句调用str函数而不调用repr函数。是不是因为调用了print函数？

class Robot:

    def __init__(self, name, build_year):
        self.name = name
        self.build_year = build_year

    def __repr__(self):
    return "Robot('" + self.name + "', " + str(self.build_year) + ")"

    def __str__(self):
    return "Name: " + self.name + ", Build Year: " + str(self.build_year)


if __name__ == "__main__":
    x = Robot("Marvin", 1979)


print(str(x))
print(x)
print(repr(x))
new = eval(repr(x))
print(new)


answer is 
Name: Marvin, Build Year: 1979
Name: Marvin, Build Year: 1979
Robot('Marvin', 1979)
Name: Marvin, Build Year: 1979

Answer 1

请参阅docs for print

像

()一样，所有非关键字参数都会转换为字符串，并写入流<...>

所以，是的，print调用了对象的__str__。