Many ways of formatting strings in Python

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There are so many ways of formatting strings i Python. For example…

You can use formatted string…

location = "New York"
temperature = 76.22
greeting = f"Temperature in {location} is {temperature}"
# Temperature in New York is 76.22

Or you can use the format method of a string with placeholders that are index or name based. The following gives the same results…

greeting = "Temperature in {} is {}".format(location, temperature)
greeting = "Temperature in {0} is {1}".format(location, temperature)
greeting = "Temperature in {1} is {0}".format(temperature, location)
greeting = "Temperature in {location} is {temperature}".format(location="New York", temperature="76.22")

You can place formatting information in the placeholder. The following will display the temperature in one decimal place…

greeting = "Temperature in {} is {:.1f}".format(location, temperature)

The following gives a field of 10 character padded with leading zeros…

greeting = "Temperature in {} is {:0>10.1f}".format(location, temperature)

The older string formatter does similarly…

greeting = "Temperature in %s is %.1f" % (location, temperature)

With named place holders, you can define a formatter function like this …

greeting_formatter = "Temperature in {location} is {temperature}".format

print(greeting_formatter(location="Dallas", temperature="82.6"))

If you need to display literal braces in the string, double it up…

greeting = "{{Hi}}: Temperature in {} is {}".format(location, temperature)
# {Hi}: Temperature in New York is 76.22

Similarly if you need a % in your string in the older style format…

greeting = "Temperature%% in %s is %.1f" % (location, temperature)
# Temperature% in New York is 76.2

If you have a dictionary, your placeholder can extract values from it like this…

weather = {"location":  "New York", "temperature": 76.22}
greeting = "Temperature in {0[location]} is {0[temperature]}".format(weather)

Or if you have a list, you can do similarly…

weather = ["New York", 76.22 ]
greeting = "Temperature in {0[0]} is {0[1]}".format(weather)

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