Consider using f-strings PYL-C0209
Performance
Minor
2 years ago
—
2 years old
Formatting a regular string which could be a f-string
85 def Echo123(self, msg1, msg2, msg3):
86 return ("1:%s 2:%s 3:%s" % (msg1.decode("utf-8"), msg2.decode("utf-8"), msg3.decode("utf-8")))
87 def EchoStruct(self, msg):
88 return ("%s" % msg) 89
90 addr = msgpackrpc.Address(mylocaladdr, port)
91 server = msgpackrpc.Server(EchoHandler())Formatting a regular string which could be a f-string
83def doRpcServer(port, stopTimeSec):
84 class EchoHandler(object):
85 def Echo123(self, msg1, msg2, msg3):
86 return ("1:%s 2:%s 3:%s" % (msg1.decode("utf-8"), msg2.decode("utf-8"), msg3.decode("utf-8"))) 87 def EchoStruct(self, msg):
88 return ("%s" % msg)
89
Description
f-strings are the fastest way to format strings as compared to the following methods:
- using format specifiers
% - using
format() - using
str.join - using
+operator to concatinate string - using
Template.substitute
Bad practice
Some less preferred ways to format strings are the following:
from string import Template
menu = ('eggs', 'spam', 42.4)
old_order = "%s and %s: %.2f ¤" % menu # [consider-using-f-string]
beginner_order = menu[0] + " and " + menu[1] + ": " + str(menu[2]) + " ¤"
joined_order = " and ".join(menu[:2])
format_order = "{} and {}: {:0.2f} ¤".format(menu[0], menu[1], menu[2])
named_format_order = "{eggs} and {spam}: {price:0.2f} ¤".format(eggs=menu[0], spam=menu[1], price=menu[2])
template_order = Template('$eggs and $spam: $price ¤').substitute(eggs=menu[0], spam=menu[1], price=menu[2])
Recommended
Consider using f-strings as shown below:
menu = ('eggs', 'spam', 42.4)
f_string_order = f"{menu[0]} and {menu[1]}: {menu[2]:0.2f} ¤"