Sometimes, while working with locations, we need a lot of data which has location points in form of latitudes and longitudes. These can be in form of a string and we desire to get tuple versions of same. Let’s discuss certain ways in which this task can be performed.
Method #1 :
Using tuple() + float() + split() + map() The combination of above functions can be used to perform this task. In this, we first split the two parts of coordinates into a list, apply float function to each of them using float() and map() and lastly it is converted to tuple using tuple().
Python3
# Python3 code to demonstrate working of# Convert location coordinates to tuple# Using tuple() + float() + split() + map()# Initializing stringtest_str = "44.6463, -49.583"# printing original stringprint("The original string is : " + str(test_str))# Convert location coordinates to tuple# Using tuple() + float() + split() + map()res = tuple(map(float, test_str.split(', ')))# printing resultprint("The coordinates after conversion to tuple are : " + str(res)) |
The original string is : 44.6463, -49.583 The coordinates after conversion to tuple are : (44.6463, -49.583)
Method #2 :
Using eval() This is the one-liner and recommended method to perform this particular task. In this, the eval(), internally detects the string and converts to floating point number separated as tuple elements.
Python3
# Python3 code to demonstrate working of# Convert location coordinates to tuple# Using eval()# Initializing stringtest_str = "44.6463, -49.583"# printing original stringprint("The original string is : " + str(test_str))# Convert location coordinates to tuple# Using eval()res = eval(test_str)# printing resultprint("The coordinates after conversion to tuple are : " + str(res)) |
The original string is : 44.6463, -49.583 The coordinates after conversion to tuple are : (44.6463, -49.583)
Method #3: Using regular expression
Approach
using regular expressions to match the latitude and longitude values in the original string. We then convert the matched strings to floats and create a tuple with the two values.
Algorithm
1. Import the re module.
2. Use a regular expression to match the latitude and longitude values in the original string.
3. Convert the matched latitude and longitude strings to floats.
4. Create a tuple with the latitude and longitude floats.
5. Return the tuple.
Python3
import redef convert_coordinates(coordinates_str): lat_str, long_str = re.findall(r'[-+]?\d*\.\d+|\d+', coordinates_str) lat_float = float(lat_str) long_float = float(long_str) return (lat_float, long_float)coordinates_str = "44.6463, -49.583"print(convert_coordinates(coordinates_str)) |
(44.6463, -49.583)
Time complexity: O(1)
Auxiliary Space: O(1)
Method 4 : using a generator expression:
step-by-step approach
Initialize a string variable test_str with the value “44.6463, -49.583”.
Use the split() method with ‘, ‘ as the delimiter to split the test_str string into a list of two string values, “44.6463” and “-49.583”.
Use a generator expression to loop through the list of string values and convert each string value to a float.
Use the tuple() constructor to create a tuple of the two floating-point numbers.
Assign the tuple of floating-point numbers to the variable coordinates.
Print the message “The coordinates after conversion to tuple are :” along with the value of the coordinates variable.
Python3
# Initializing stringtest_str = "44.6463, -49.583"# Using a generator expression to convert the coordinates to a tuplecoordinates = tuple(float(coord) for coord in test_str.split(', '))# Printing the resultprint("The coordinates after conversion to tuple are :", coordinates) |
The coordinates after conversion to tuple are : (44.6463, -49.583)
Time complexity of O(n), where n is the length of the input string.
The auxiliary space complexity is O(n), as it creates a tuple of n floating-point numbers.
Method 5: using numpy:
- Import the numpy library.
- Initialize a string variable test_str with a string value.
- Print the original string.
- Use the numpy fromstring() method to convert the string to a numpy array.
- Split the string on the comma delimiter, and pass the resulting list to the fromstring() method.
- Set the dtype parameter of the fromstring() method to float to ensure that the array values are treated as floating-point numbers.
- Print the resulting numpy array.
Python3
import numpy as np# input stringtest_str = "44.6463, -49.583"# convert string to 1D numpy array of float valuesarr = np.fromstring(test_str, sep=", ", dtype=float)# reshape array to a 2D array of shape (1, 2)res = arr.reshape((1, 2))# print resultprint("The coordinates after conversion to tuple are:", res)#This code is contributed by Pushpa. |
Output: The coordinates after conversion to tuple are: [[ 44.6463 -49.583 ]]
Time complexity: O(n), where n is the length of the string being converted to a numpy array.
Space complexity: O(n), where n is the length of the string being converted to a numpy array. This is because the resulting numpy array will take up space in memory proportional to the length of the string.
