Python Variable Data Type Conversion

Python Variable Data Type Conversion – In application development, there could be scenarios during which a value of a data type should be converted to a value of other data type.

For doing this conversion from data type to another, python provides following built-in functions :

Convert to Integer or Long

int(x) is used to convert x to int

int(x,base) is used if x is a string, and base specifies thebase of the value in x to be converted to integer. If base is not specified when x is a string, 10 is taken as default base.

Following program demonstrates the conversion of float, string and complex numbers to int.

example.py – Python Program

float_value = 5.2
str_value = "34"
complex_value = 3.14j

float_value_to_int = int(float_value)
str_value_to_int = int(str_value)
str_value_to_int_base_8 = int(str_value,8)
str_value_to_int_base_6 = int(str_value,6)
complex_value_to_int = int(abs(complex_value))

print(float_value_to_int)
print(str_value_to_int)
print(str_value_to_int_base_8)
print(str_value_to_int_base_6)
print(complex_value_to_int)
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Output

5
34
28
22
3

Note : By default, if the value could not be accommodated in an integer, the data type is automatically upgraded to long by the python interpreter. If the value is so long that it could not fit in an integer, then we got python interpreter to upgrade it to long without our attention required.

Convert to Float

float(x) is used to convert x to float.

Following program demonstrates the conversion of int, string and complex numbers to float.

example.py – Python Program

int_value = 254
str_value = "34.68"
complex_value = 3.14j

long_value_to_float = float(int_value)
str_value_to_float = float(str_value)
complex_value_to_float = float(abs(complex_value))

print(long_value_to_float)
print(str_value_to_float)
print(complex_value_to_float)
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Output

254.0
34.68
3.14

Convert to Complex

complex(real) is used to convert x to complex value with no imaginary value as 0.

complex(real, imag) is used to convert x to complex value.

example.py – Python Program

real_value = 254
imaginary_value = 394

to_complex_only_real = complex(real_value)
to_complex = complex(real_value, imaginary_value)

print(to_complex_only_real)
print(to_complex)
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Output

(254+0j)
(254+394j)

Convert to Character

chr(x) converts the integer x to character.

example.py – Python Program

int_value_1 = 69
int_value_2 = 81

int_to_character_1 = chr(int_value_1)
int_to_character_2 = chr(int_value_2)

print(int_to_character_1)
print(int_to_character_2)
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Output

E
Q

Conversion to String

str(x) is used to convert x to string

Following program demonstrates the conversion of float, int, complex number, tuple, list and dictionary to string.

example.py – Python Program

float_value = 56.369
long_value = 6369742212323693323265
complex_value = (214 + 254j)
tuple_value = ("John","spy",42)
list_value = [1,'India',36.45,"New Delhi"]
dict_value = {'country':'India','capital':'New Delhi'}

float_value_to_string = str(float_value)
long_value_to_string = str(long_value)
complex_value_to_string = str(complex_value)
tuple_value_to_string = str(tuple_value)
list_value_to_string = str(list_value)
dict_value_to_string = str(dict_value)

print(float_value_to_string)
print(long_value_to_string)
print(complex_value_to_string)
print(tuple_value_to_string)
print(list_value_to_string)
print(dict_value_to_string)
print()
print(float_value_to_string + long_value_to_string + complex_value_to_string +
      tuple_value_to_string + list_value_to_string + dict_value_to_string)
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Output

56.369
6369742212323693323265
(214+254j)
('spy', 42, 'John')
[1, 'India', 36.45, 'New Delhi']
{'country': 'India', 'capital': 'New Delhi'}

56.3696369742212323693323265(214+254j){'spy', 42, 'John'}[1, 'India', 36.45, 'New Delhi']{'country': 'India', 'capital': 'New Delhi'}

Convert to Tuple

tuple(x) converts x to tuple.

example.py – Python Program

str_value = "hello"
str_to_tuple = tuple(str_value)

print(str_to_tuple)
print(str_to_tuple[0])
print(str_to_tuple[1])
print(str_to_tuple[2])
print(str_to_tuple[3])
print(str_to_tuple[4])
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Output

('h', 'e', 'l', 'l', 'o')
h
e
l
l
o

The string is made up of characters and when the string is converted to tuple, the characters would become elements of the tuple.

Convert to List

list(x) converts x to tuple with elements that are “iteratable over” in x. If x is a string, string could be iterated over its characters and characters would become the elements of the newly formed list.

example.py – Python Program

str_value = "hello"
str_to_list = list(str_value)
print(str_to_list)
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Output :

['h', 'e', 'l', 'l', 'o']

Convert to Set

set(x) converts x to tuple with elements that are “iteratable over” in x. If x is a string, string could be iterated over its characters and characters would become the elements of the newly formed set. And only unique elements are allowed in a set.

example.py – Python Program

str_value = "hello Nemo!"
str_to_list = set(str_value)
print(str_to_set)
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Output

{'h', 'o', 'l', ' ', '!', 'm', 'N', 'e'}

Convert to Frozen Set

frozenset(x) converts x to tuple with elements that are “iteratable over” in x. If x is a string, string could be iterated over its characters and characters would become the elements of the newly formed list.

example.py – Python Program

str_value = "hello Nemo!"
str_to_frozenset = frozenset(str_value)
print(str_to_frozenset)
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Output

frozenset({' ', 'm', 'N', 'h', 'l', 'e', '!', 'o'})

Convert to Dictionary

dict(x) converts x, sequence or list of tuples (key, value), into dictionary.

Python Variable Data Type Conversion from list of tuples to dictionary

example.py – Python Program

tupils_list = z = [('1','a'), ('2','b'), ('3','c')]
str_to_dict = dict(tupils_list)
print(str_to_dict)
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Output

{'1': 'a', '2': 'b', '3': 'c'}

Conclusion

In this Python Tutorial, we have learnt Python Variable Data Type Conversion.