python 有用的python片段

Posted 2021-05-09

##############################################
# Compare 2 dicts except some keys
def compare_dict(d1, d2, ignore):
  for k in d1:
    if k in ignore:
      continue
    try:
      if d1[k] != d2[k]:
        return False
    except KeyError:
      return False
  return True

d1 = {'price': 1000.0, 'position': 'long', 'action': 'hold', 'warning': ''}
d2 = {'price': 1001.0, 'position': '', 'action': 'hold', 'warning': ''}
d3 = {'price': 1002.0, 'position': 'long', 'action': 'hold', 'warning': ''}

print(compare_dict(d1, d2, ['price']))
print(compare_dict(d2, d3, ['price']))
print(compare_dict(d1, d3, ['price']))



##############################################
# Convert a dictionary containing unicode string, non string into a json loadable object
def convert_dict_to_json(data, convert_unicode_to_string=True):
    if isinstance(data, basestring):
        return str(data)
    elif isinstance(data, unicode):
        if convert_unicode_to_string:
            return data.encode('utf-8')
        else:
            return data
    elif isinstance(data, collections.Mapping):
        return dict(map(convert_dict_to_json, data.iteritems()))
    elif isinstance(data, collections.Iterable):
        return type(data)(map(convert_dict_to_json, data))
    else:
        return str(data)

##############################################
# Check if a key is in a dict
if myKey in dict:
    do_some_work
else:
    pass
# Option 2 - try exception
try:
    do_some_work(dict[myKey])
except KeyError:
    pass

##############################################
# String format
>>> "{:0>2}".format("1")  # Works for both numbers and strings.
'01'
>>> "{:02}".format(1)  # Only works for numbers.
'01'


##############################################
# Connect to HSQLDB 

import jaydebeapi

conn = jaydebeapi.connect("org.hsqldb.jdbcDriver", 
                          "jdbc:hsqldb:hsql://localhost:9000/db", 
                          ["SA", ""], 
                          "/home/user_id/hsqldb-2.4.0/hsqldb/lib/hsqldb.jar",)
curs = conn.cursor()
query = """
SELECT * 
FROM test
WHERE id = ?
"""
curs.execute(query, (some_id))
print curs.fetchall()
curs.close()
conn.close()