59 lines
1.3 KiB
Markdown
59 lines
1.3 KiB
Markdown
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---
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title: Python Complex Numbers
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---
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Complex numbers have a real and an imaginary part, each represented by a floating point number.
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The imaginary part of a complex number can be created using an imaginary literal, this results in a complex number with a real part of `0.0`:
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```python
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>>> a = 3.5j
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>>> type(a)
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<class 'complex'>
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>>> print(a)
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3.5j
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>>> a.real
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0.0
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>>> a.imag
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3.5
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```
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No literal exists for creating a complex number with non-zero real and imaginary parts. To create a non-zero real part complex number, add an imaginary literal to a floating point number:
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```python
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>>> a = 1.1 + 3.5j
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>>> type(a)
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<class 'complex'>
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>>> print(a)
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(1.1+3.5j)
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>>> a.real
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1.1
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>>> a.imag
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3.5
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```
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Or use the <a href='https://docs.python.org/3/library/functions.html#complex' target='_blank' rel='nofollow'>complex constructor</a>.
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```python
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class complex([real[, imag]])
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```
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The arguments used to call the complex constructor can be of numeric (including `complex`) type for either parameter:
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```python
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>>> complex(1, 1)
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(1+1j)
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>>> complex(1j, 1j)
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(-1+1j)
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>>> complex(1.1, 3.5)
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(1.1+3.5j)
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>>> complex(1.1)
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(1.1+0j)
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>>> complex(0, 3.5)
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3.5j
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```
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A `string` can also be used as the argument. No second argument is allowed if a string is used as an argument
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```python
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>>> complex("1.1+3.5j")
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(1.1+3.5j)
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```
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