In Python, formatting string using concatenation(+) can be messy. Luckily, string.format() make it easier and cleaner for you to format string. This method will parse your string and replace the placeholder({}) that you put in with the parameters that you pass to it. Here is a simple example.
"My name is {} {}".format("Joe", "Smith") # Output: My name is Joe Smith
Placeholder & parameter order
The placeholders({}) and the parameters don't have to follow the same order. You can specify a specific order for the placeholders and parameters. Here are some examples.
# Re-arranging the order of display without changing the arguments. "{1} {0}".format("zero", "one") # Output: one zero # Use named placeholders: first and last. "My name is {first} {last}".format(last="Smith", first="Joe") # Output: My name is Joe Smith
Left or right alignment
# Allocate 5 character spaces for Joe & 7 for Smith. "{:5s}|{:7s}|".format("Joe", "Smith") # Output: Joe |Smith | # By default, left alignment is assumed. For right alignment, add > "{:>5s}|{:>7s}|".format("Joe", "Smith") # Output: Joe| Smith|
Format numbers
# Padding number with zeros. "{:06}".format(3) # Output: 000003 # Format pi up to 2 decimal points. pi=3.14159 "{:.2f}".format(pi) # Output: 3.14
About the author
Xuan Ngo is the founder of OpenWritings.net. He currently lives in Montreal, Canada. He loves to write about programming and open source subjects.