Type conversions

Type conversions#

Converting numbers to strings#

If you have an integer or float number i, you can make a string out of it with str(i):

    text = str(2000)

Alternatively, you can insert variables into an f-string (since Python 3.6):

number = 2000
text = f"the year is: {number}"
text

'the year is: 2000'

Type conversionsm#

Converting numbers to strings#

If you have an integer or float number i, you can make a string out of it with str(i):

    text = str(2000)

Alternatively, you can insert variables into an f-string (since Python 3.6):

    number = 2000
    text = f"the year is: {number}"

Format strings allow you to express floats with a given precision:

    pi = 3.14159
    text = f"{pi:4.2f}"

Converting strings to numbers#

If you have a string s, you can make an integer out of it with int(s):

    number = int("2000")
    number

2000

The same works for a float:

    number = float("3.14159")

Other type conversions#

The functions int(), float() and str() change the type of the given data. They are therefore called type conversions. There is a conversion functions for each Python data type. Try the following:

    int('5.5')

---------------------------------------------------------------------------

ValueError                                Traceback (most recent call last)

Cell In[8], line 1
----> 1 int('5.5')


ValueError: invalid literal for int() with base 10: '5.5'

Format strings allow you to express floats with a given precision:

pi = 3.14159
text = f"{pi:4.2f}"

Converting strings to numbers#

If you have a string s, you can make an integer out of it with int(s):

number = int("2000")
number

2000

The same works for a float:

    number = float("3.14159")

Other type conversions#

The functions int(), float() and str() change the type of the given data. They are therefore called type conversions. There is a conversion functions for each Python data type. Try the following:

    int('5.5')

---------------------------------------------------------------------------

ValueError                                Traceback (most recent call last)

Cell In[14], line 1
----> 1 int('5.5')


ValueError: invalid literal for int() with base 10: '5.5'

    float(5)

5.0

    str(5.5)

'5.5'

    list("ABC")

['A', 'B', 'C']

    tuple([1, 2, 3])

(1, 2, 3)

    dict([('A', 1), ('B', 2)])

{'A': 1, 'B': 2}

    set([1, 2, 2, 3])

{1, 2, 3}