python string commonly used functions

Today saw on the public micro-channel number of the article again python learning development, there are a number of questions face the python, python do not know what happened recently learned, simply learn about this article ah! ! The first to write about some strings commonly used functions. (Ps: I have too much food, if the wrong place at any time to welcome chiefs scolded ..xixixii)

0x01: format string

Format string can be very helpful to us what we want out of output, it is also very easy to use, there are several forms below.

# Format string
print ( 'hello, {0} {1} {2}'. format ( 'zhong', 'yuan', 'gong')) # formatted by the position
print ( 'hello, {name}, my name is {self} !!'. format (name = 'tom', self = 'sir')) # key by filling
l=['tom', 'sir']
print ( 'hello, {l [0]}, my name is {l [1]} !!'. format (l = l)) # by filling the array index
m={'name': 'tom', 'self': 'sir'}
print ( 'hello, {m [name]}, my name is {m [self]} !!'. format (m = m)) # key by filling the dictionary, key without quotes

The above results are output: hello, tom, my name is sir !!

0x02: String sensitive issues

English case conversion on the issue of string can be achieved by following a few functions

# Capitalized
a = 'hello,zHong yUan GoNg!!'
print(a.title())
# ALL CAPS
print(a.upper())
# All lowercase
print(a.lower())
The first letter of the first word capitalized #
print(a.capitalize())

The output for the first time:

The Hello, Zhong Yuan Gong !!
HELLO, ZHONG YUAN GONG !!
the Hello, zhong Yuan Gong !!
the Hello, zhong Yuan Gong !!

0x03: String slices

d = '123456789'
# Get the first 3-6 characters　　　　　　
print (d [2: 6]) # entered here is the index of the string, the slicing Python, the former containing the free, as output here is the index of the substring 2-5, rather than under standard substring 2-6.
# Get the last two characters
print(d[-2:])
# Reverse the string
print(d[::-1])

Output:

3456
89
987654321

0x04: Delete spaces in the string

c = '   hello world !!!     '
# Remove the string at the beginning and end of the space
print(c.strip())
# Remove the strings of spaces left
print(c.lstrip())
# Remove spaces to the right of the string
print(c.rstrip())
# String remove all spaces
print(c.replace(' ',''))

Output as follows:

hello world !!!
hello world !!!
hello world !!!
helloworld!!!

Note: This function is not to strip and split functions confused, the former is to delete the specified character string, the default is a space, which is divided with a specified character string, the default is a space

0x05: change the string encoding

Sometimes we conduct file storage is garbled, this time, we change it encodes OK. Follows

# Convert string encoding
e = 'hello, zhongyuan university, you are well! '
print(e.encode('utf-8'))

python string commonly used functions

Guess you like