Imperial City PK
Formatting strings in Python currently has two camps: % and format, which one should we choose?
Since Python 2.6 introduced format as a way to format strings, I don't think % or format is even a question. Look down the page if you don't believe me.
# Define a coordinate value c = (250, 250) # Use % to format s1 = "Enemy coordinates: %s" % c
The above code will obviously throw a TypeError as follows:
TypeError: not all arguments converted during string formatting
Formatting requirements like these we need to write in the ugly format below to make it work:
# Define a coordinate value c = (250, 250) # Use % ugly formatting... s1 = "Enemy coordinates: %s" % (c,)
The above problem does not exist with format:
# Define a coordinate value
c = (250, 250)
# Formatting with format
s2 = "Enemy coordinates：{}".format(c)
Obviously, this one reason above is enough for you to use format in future projects.
new feature
f-strings was added in Python 3.6:
In[1]: name = "Q1mi"
In[2]: age = 18
In[3]: f"My name is {name}.I'm {age}"
Out[3]: "My name is 'm 18"
Common Format Usage
By position
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'
Through object properties
In[1]: class Person(object):
...: def __init__(self, name, age):
...: = name
...: = age
...: def __str__(self):
...: return "This guy is {}, {} 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 subscripting
In[1]: "{0[0]} is {0[1]} years old.".format(data)
Out[1]: 'Q1mi is 18 years old.'
Filling and Alignment
Fill is often used with alignment
^, <, > are centered, left-aligned, and right-aligned, respectively, followed by a width
The character with padding after the : sign can only be one character, the default is padded with spaces if not specified.
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
Supplement a string with its own zfill() method:
The Python zfill() method returns a string of the specified length, with the original string right-justified and padded with zeros in front.
zfill() method syntax: (width)
The parameter width specifies the length of the string. The original string is right-aligned and padded with zeros.
Returns a string of the specified length.
In[1]: "18".zfill(10) Out[1]: '0000000018'
Precision and typef
Precision is often used with type f.
In[1]: "{:.2f}".format(3.1415926)
Out[1]: '3.14'
where .2 denotes a precision of length 2 and f denotes a float type.
Other Binary
The main thing is the binary system. b, d, o, and x are binary, decimal, octal, and hexadecimal, respectively.
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'
summarize
The above is a small introduction to python's formatting output (format,%) examples in detail, I hope to help you, if you have any questions please leave me a message, I will promptly reply to you. I would also like to thank you very much for your support of my website!