% Or% format Python should be used to format or format string?

Python% or format should be used to format string?

 

% Or format

Imperial PK

Python string formatting There are two camps:% and format, what should we choose?

Since the introduction of the format Python2.6 this method after the format string, I think% or format this is simply not a problem. Do not believe you look down.

# Define a coordinate value 
C = (250, 250) 
#% formatted using 
s1 = "enemy coordinates:% s"% c

Obviously the above code will throw a following TypeError:

TypeError: not all arguments converted during string formatting

As the demand for such formatted we need to write the following format ugly job:

# Define a coordinate value 
C = (250, 250) 
#% using ugly format ... 
S1 = "enemy coordinates:% s"% (c, )

And uses the format would not exist the above questions:

# Define a coordinate value 
C = (250, 250) 
# format using format 
s2 = "enemy coordinates: {}". Format (c )

Obviously, above this one we had reason enough for you to use the format in future projects.

New features

Python3.6 added in the F-strings :

In[1]: name = "Q1mi"
In[2]: age = 18
In[3]: f"My name is {name}.I'm {age}"
Out[3]: "My name is Q1mi.I'm 18"

Common format usage

By location

In[1]: data = ["Q1mi", 18]
In[2]: "Name:{0}, Age:{1}".format(*data)
Out[2]: 'Name:Q1mi, Age:18'

By Keyword

In[1]: data = {"name": "Q1mi", "age": 18}
In[2]: "Name:{name}, Age:{age}".format(**data)
Out[2]: 'Name:Q1mi, Age:18'

Object properties

In[1]: class Person(object):
   ...:     def __init__(self, name, age):
   ...:         self.name = name
   ...:         self.age = age
   ...:     def __str__(self):      
   ...:         return "This guy is {self.name}, {self.age} years old.".format(self=self)
   ...:     
In[2]: p = Person("Q1mi", 18)
In[3]: str(p)
Out[3]: 'This guy is Q1mi, 18 years old.'

By subscript

In[1]: "{0[0]} is {0[1]} years old.".format(data)
Out[1]: 'Q1mi is 18 years old.'

Filling aligned

Often used in conjunction with aligned filling

^, <,> Are centered, left aligned, right aligned, the width of the back

: Back-filled with a number of characters, only one character is not specified, the default is filled with spaces.

In[1]: "{:>10}".format('18')
Out[1]: '        18'
In[2]: "{:0>10}".format('18')
Out[2]: '0000000018'
In[3]: "{:A>10}".format('18')
Out[3]: 'AAAAAAAA18

A supplementary string comes zfill () Method:

Python zfill () method returns a specified length of the original string right justified, padded with zeros in front.

zfill () method syntax: str.zfill (width)

Parameters width length of the string. Original string right justified, padded with zeros in front.

Returns a string of specified length.

In[1]: "18".zfill(10)
Out[1]: '0000000018'

Accuracy and type f

Accuracy often used in conjunction with type f.

In[1]: "{:.2f}".format(3.1415926)
Out[1]: '3.14'

Wherein an accuracy of .2 represents the length of 2, f denotes a float.

Other band

The main band is a, b, d, o, x are binary, decimal, octal, hexadecimal.

In[1]: "{:b}".format(18)
Out[1]: '10010'
In[2]: "{:d}".format(18)
Out[2]: '18'
In[3]: "{:o}".format(18)
Out[3]: '22'
In[4]: "{:x}".format(18)
Out[4]: '12'

Thousands Separator

In[1]: "{:,}".format(1234567890)
Out[1]: '1,234,567,890

% Or format

Imperial PK

Python string formatting There are two camps:% and format, what should we choose?

Since the introduction of the format Python2.6 this method after the format string, I think% or format this is simply not a problem. Do not believe you look down.

# Define a coordinate value 
C = (250, 250) 
#% formatted using 
s1 = "enemy coordinates:% s"% c

Obviously the above code will throw a following TypeError:

TypeError: not all arguments converted during string formatting

As the demand for such formatted we need to write the following format ugly job:

# Define a coordinate value 
C = (250, 250) 
#% using ugly format ... 
S1 = "enemy coordinates:% s"% (c, )

And uses the format would not exist the above questions:

# Define a coordinate value 
C = (250, 250) 
# format using format 
s2 = "enemy coordinates: {}". Format (c )

Obviously, above this one we had reason enough for you to use the format in future projects.

New features

Python3.6 added in the F-strings :

In[1]: name = "Q1mi"
In[2]: age = 18
In[3]: f"My name is {name}.I'm {age}"
Out[3]: "My name is Q1mi.I'm 18"

Common format usage

By location

In[1]: data = ["Q1mi", 18]
In[2]: "Name:{0}, Age:{1}".format(*data)
Out[2]: 'Name:Q1mi, Age:18'

By Keyword

In[1]: data = {"name": "Q1mi", "age": 18}
In[2]: "Name:{name}, Age:{age}".format(**data)
Out[2]: 'Name:Q1mi, Age:18'

Object properties

In[1]: class Person(object):
   ...:     def __init__(self, name, age):
   ...:         self.name = name
   ...:         self.age = age
   ...:     def __str__(self):      
   ...:         return "This guy is {self.name}, {self.age} years old.".format(self=self)
   ...:     
In[2]: p = Person("Q1mi", 18)
In[3]: str(p)
Out[3]: 'This guy is Q1mi, 18 years old.'

By subscript

In[1]: "{0[0]} is {0[1]} years old.".format(data)
Out[1]: 'Q1mi is 18 years old.'

Filling aligned

Often used in conjunction with aligned filling

^, <,> Are centered, left aligned, right aligned, the width of the back

: Back-filled with a number of characters, only one character is not specified, the default is filled with spaces.

In[1]: "{:>10}".format('18')
Out[1]: '        18'
In[2]: "{:0>10}".format('18')
Out[2]: '0000000018'
In[3]: "{:A>10}".format('18')
Out[3]: 'AAAAAAAA18

A supplementary string comes zfill () Method:

Python zfill () method returns a specified length of the original string right justified, padded with zeros in front.

zfill () method syntax: str.zfill (width)

Parameters width length of the string. Original string right justified, padded with zeros in front.

Returns a string of specified length.

In[1]: "18".zfill(10)
Out[1]: '0000000018'

Accuracy and type f

Accuracy often used in conjunction with type f.

In[1]: "{:.2f}".format(3.1415926)
Out[1]: '3.14'

Wherein an accuracy of .2 represents the length of 2, f denotes a float.

Other band

The main band is a, b, d, o, x are binary, decimal, octal, hexadecimal.

In[1]: "{:b}".format(18)
Out[1]: '10010'
In[2]: "{:d}".format(18)
Out[2]: '18'
In[3]: "{:o}".format(18)
Out[3]: '22'
In[4]: "{:x}".format(18)
Out[4]: '12'

Thousands Separator

In[1]: "{:,}".format(1234567890)
Out[1]: '1,234,567,890