Python字典添加,删除,查询等相关操作方法详解


Posted in Python onFebruary 07, 2020

一、创建增加修改

1、实现代码

#创建
stu_info = { "xiedi":28, "liuhailin":27,"daiqiao":30,"hanwenhai":25,"chenqun":38}
print(stu_info)
#增加
stu_info["luoahong"]=32
print(stu_info)
#修改
stu_info["xiedi"]=29
print(stu_info)

输出结果

{'xiedi': 28, 'liuhailin': 27, 'daiqiao': 30, 'hanwenhai': 25, 'chenqun': 38}
{'xiedi': 28, 'liuhailin': 27, 'daiqiao': 30, 'hanwenhai': 25, 'chenqun': 38, 'luoahong': 32}
{'xiedi': 29, 'liuhailin': 27, 'daiqiao': 30, 'hanwenhai': 25, 'chenqun': 38, 'luoahong': 32}

二、删除(del)

1、实现代码

del stu_info["chenqun"]
print(stu_info)

2、输出结果

{'xiedi': 29, 'liuhailin': 27, 'daiqiao': 30, 'hanwenhai': 25, 'luoahong': 32}

 1、Dict_DelItem 

int
PyDict_DelItem(PyObject *op, PyObject *key)
{
  Py_hash_t hash;
  assert(key);
  if (!PyUnicode_CheckExact(key) ||
    (hash = ((PyASCIIObject *) key)->hash) == -1) {
    hash = PyObject_Hash(key);
    if (hash == -1)
      return -1;
  }

  return _PyDict_DelItem_KnownHash(op, key, hash);
}

2、Dict_DelItem_KnownHash

int
_PyDict_DelItem_KnownHash(PyObject *op, PyObject *key, Py_hash_t hash)
{
  Py_ssize_t ix;
  PyDictObject *mp;
  PyObject *old_value;

  if (!PyDict_Check(op)) {
    PyErr_BadInternalCall();
    return -1;
  }
  assert(key);
  assert(hash != -1);
  mp = (PyDictObject *)op;
  ix = (mp->ma_keys->dk_lookup)(mp, key, hash, &old_value);
  if (ix == DKIX_ERROR)
    return -1;
  if (ix == DKIX_EMPTY || old_value == NULL) {
    _PyErr_SetKeyError(key);
    return -1;
  }

  // Split table doesn't allow deletion. Combine it.
  if (_PyDict_HasSplitTable(mp)) {
    if (dictresize(mp, DK_SIZE(mp->ma_keys))) {
      return -1;
    }
    ix = (mp->ma_keys->dk_lookup)(mp, key, hash, &old_value);
    assert(ix >= 0);
  }

  return delitem_common(mp, hash, ix, old_value);
}

/* This function promises that the predicate -> deletion sequence is atomic
 * (i.e. protected by the GIL), assuming the predicate itself doesn't
 * release the GIL.
 */

3、PyDict_DelItemIf

int
_PyDict_DelItemIf(PyObject *op, PyObject *key,
         int (*predicate)(PyObject *value))
{
  Py_ssize_t hashpos, ix;
  PyDictObject *mp;
  Py_hash_t hash;
  PyObject *old_value;
  int res;

  if (!PyDict_Check(op)) {
    PyErr_BadInternalCall();
    return -1;
  }
  assert(key);
  hash = PyObject_Hash(key);
  if (hash == -1)
    return -1;
  mp = (PyDictObject *)op;
  ix = (mp->ma_keys->dk_lookup)(mp, key, hash, &old_value);
  if (ix == DKIX_ERROR)
    return -1;
  if (ix == DKIX_EMPTY || old_value == NULL) {
    _PyErr_SetKeyError(key);
    return -1;
  }

  // Split table doesn't allow deletion. Combine it.
  if (_PyDict_HasSplitTable(mp)) {
    if (dictresize(mp, DK_SIZE(mp->ma_keys))) {
      return -1;
    }
    ix = (mp->ma_keys->dk_lookup)(mp, key, hash, &old_value);
    assert(ix >= 0);
  }

  res = predicate(old_value);
  if (res == -1)
    return -1;

  hashpos = lookdict_index(mp->ma_keys, hash, ix);
  assert(hashpos >= 0);

  if (res > 0)
    return delitem_common(mp, hashpos, ix, old_value);
  else
    return 0;
}

二、删除pop(k)

实现

stu_info = { "xiedi":28, "liuhailin":27,"daiqiao":30,"hanwenhai":25,"chenqun":38}
print(stu_info)
stu_info.pop("liuhailin")
print(stu_info)

输出结果:

{'xiedi': 28, 'liuhailin': 27, 'daiqiao': 30, 'hanwenhai': 25, 'chenqun': 38}
{'xiedi': 28, 'daiqiao': 30, 'hanwenhai': 25, 'chenqun': 38}

1、_PyDict_Pop

PyObject *
_PyDict_Pop(PyObject *dict, PyObject *key, PyObject *deflt)
{
  Py_hash_t hash;

  if (((PyDictObject *)dict)->ma_used == 0) {
    if (deflt) {
      Py_INCREF(deflt);
      return deflt;
    }
    _PyErr_SetKeyError(key);
    return NULL;
  }
  if (!PyUnicode_CheckExact(key) ||
    (hash = ((PyASCIIObject *) key)->hash) == -1) {
    hash = PyObject_Hash(key);
    if (hash == -1)
      return NULL;
  }
  return _PyDict_Pop_KnownHash(dict, key, hash, deflt);
}

2、_PyDict_Pop_KnownHash

/* Internal version of dict.pop(). */
PyObject *
_PyDict_Pop_KnownHash(PyObject *dict, PyObject *key, Py_hash_t hash, PyObject *deflt)
{
  Py_ssize_t ix, hashpos;
  PyObject *old_value, *old_key;
  PyDictKeyEntry *ep;
  PyDictObject *mp;

  assert(PyDict_Check(dict));
  mp = (PyDictObject *)dict;

  if (mp->ma_used == 0) {
    if (deflt) {
      Py_INCREF(deflt);
      return deflt;
    }
    _PyErr_SetKeyError(key);
    return NULL;
  }
  ix = (mp->ma_keys->dk_lookup)(mp, key, hash, &old_value);
  if (ix == DKIX_ERROR)
    return NULL;
  if (ix == DKIX_EMPTY || old_value == NULL) {
    if (deflt) {
      Py_INCREF(deflt);
      return deflt;
    }
    _PyErr_SetKeyError(key);
    return NULL;
  }

  // Split table doesn't allow deletion. Combine it.
  if (_PyDict_HasSplitTable(mp)) {
    if (dictresize(mp, DK_SIZE(mp->ma_keys))) {
      return NULL;
    }
    ix = (mp->ma_keys->dk_lookup)(mp, key, hash, &old_value);
    assert(ix >= 0);
  }

  hashpos = lookdict_index(mp->ma_keys, hash, ix);
  assert(hashpos >= 0);
  assert(old_value != NULL);
  mp->ma_used--;
  mp->ma_version_tag = DICT_NEXT_VERSION();
  dictkeys_set_index(mp->ma_keys, hashpos, DKIX_DUMMY);
  ep = &DK_ENTRIES(mp->ma_keys)[ix];
  ENSURE_ALLOWS_DELETIONS(mp);
  old_key = ep->me_key;
  ep->me_key = NULL;
  ep->me_value = NULL;
  Py_DECREF(old_key);

  ASSERT_CONSISTENT(mp);
  return old_value;
}

三、随机删除一个元素popitem()

stu_info = { "xiedi":28, "liuhailin":27,"daiqiao":30,"hanwenhai":25,"chenqun":38}
print(stu_info)
stu_info.popitem()
print(stu_info)

输出结果:

{'xiedi': 28, 'liuhailin': 27, 'daiqiao': 30, 'hanwenhai': 25, 'chenqun': 38}
{'xiedi': 28, 'liuhailin': 27, 'daiqiao': 30, 'hanwenhai': 25}

1、dict_popitem_impl

/*[clinic input]
dict.popitem

Remove and return a (key, value) pair as a 2-tuple.

Pairs are returned in LIFO (last-in, first-out) order.
Raises KeyError if the dict is empty.
[clinic start generated code]*/

static PyObject *
dict_popitem_impl(PyDictObject *self)
/*[clinic end generated code: output=e65fcb04420d230d input=1c38a49f21f64941]*/
{
  Py_ssize_t i, j;
  PyDictKeyEntry *ep0, *ep;
  PyObject *res;

  /* Allocate the result tuple before checking the size. Believe it
   * or not, this allocation could trigger a garbage collection which
   * could empty the dict, so if we checked the size first and that
   * happened, the result would be an infinite loop (searching for an
   * entry that no longer exists). Note that the usual popitem()
   * idiom is "while d: k, v = d.popitem()". so needing to throw the
   * tuple away if the dict *is* empty isn't a significant
   * inefficiency -- possible, but unlikely in practice.
   */
  res = PyTuple_New(2);
  if (res == NULL)
    return NULL;
  if (self->ma_used == 0) {
    Py_DECREF(res);
    PyErr_SetString(PyExc_KeyError, "popitem(): dictionary is empty");
    return NULL;
  }
  /* Convert split table to combined table */
  if (self->ma_keys->dk_lookup == lookdict_split) {
    if (dictresize(self, DK_SIZE(self->ma_keys))) {
      Py_DECREF(res);
      return NULL;
    }
  }
  ENSURE_ALLOWS_DELETIONS(self);

  /* Pop last item */
  ep0 = DK_ENTRIES(self->ma_keys);
  i = self->ma_keys->dk_nentries - 1;
  while (i >= 0 && ep0[i].me_value == NULL) {
    i--;
  }
  assert(i >= 0);

  ep = &ep0[i];
  j = lookdict_index(self->ma_keys, ep->me_hash, i);
  assert(j >= 0);
  assert(dictkeys_get_index(self->ma_keys, j) == i);
  dictkeys_set_index(self->ma_keys, j, DKIX_DUMMY);

  PyTuple_SET_ITEM(res, 0, ep->me_key);
  PyTuple_SET_ITEM(res, 1, ep->me_value);
  ep->me_key = NULL;
  ep->me_value = NULL;
  /* We can't dk_usable++ since there is DKIX_DUMMY in indices */
  self->ma_keys->dk_nentries = i;
  self->ma_used--;
  self->ma_version_tag = DICT_NEXT_VERSION();
  ASSERT_CONSISTENT(self);
  return res;
}

四、查找(key值在字典中存在) 

1、dict_keys

static PyObject *
dict_keys(PyDictObject *mp)
{
  PyObject *v;
  Py_ssize_t i, j;
  PyDictKeyEntry *ep;
  Py_ssize_t n, offset;
  PyObject **value_ptr;

 again:
  n = mp->ma_used;
  v = PyList_New(n);
  if (v == NULL)
    return NULL;
  if (n != mp->ma_used) {
    /* Durnit. The allocations caused the dict to resize.
     * Just start over, this shouldn't normally happen.
     */
    Py_DECREF(v);
    goto again;
  }
  ep = DK_ENTRIES(mp->ma_keys);
  if (mp->ma_values) {
    value_ptr = mp->ma_values;
    offset = sizeof(PyObject *);
  }
  else {
    value_ptr = &ep[0].me_value;
    offset = sizeof(PyDictKeyEntry);
  }
  for (i = 0, j = 0; j < n; i++) {
    if (*value_ptr != NULL) {
      PyObject *key = ep[i].me_key;
      Py_INCREF(key);
      PyList_SET_ITEM(v, j, key);
      j++;
    }
    value_ptr = (PyObject **)(((char *)value_ptr) + offset);
  }
  assert(j == n);
  return v;
}

2、PyDict_Keys

PyObject *
PyDict_Keys(PyObject *mp)
{
  if (mp == NULL || !PyDict_Check(mp)) {
    PyErr_BadInternalCall();
    return NULL;
  }
  return dict_keys((PyDictObject *)mp);
}

PyObject *
PyDict_Values(PyObject *mp)
{
  if (mp == NULL || !PyDict_Check(mp)) {
    PyErr_BadInternalCall();
    return NULL;
  }
  return dict_values((PyDictObject *)mp);
}

五、get(k)

1、dict_get_impl

static PyObject *
dict_get_impl(PyDictObject *self, PyObject *key, PyObject *default_value)
/*[clinic end generated code: output=bba707729dee05bf input=279ddb5790b6b107]*/
{
  PyObject *val = NULL;
  Py_hash_t hash;
  Py_ssize_t ix;

  if (!PyUnicode_CheckExact(key) ||
    (hash = ((PyASCIIObject *) key)->hash) == -1) {
    hash = PyObject_Hash(key);
    if (hash == -1)
      return NULL;
  }
  ix = (self->ma_keys->dk_lookup) (self, key, hash, &val);
  if (ix == DKIX_ERROR)
    return NULL;
  if (ix == DKIX_EMPTY || val == NULL) {
    val = default_value;
  }
  Py_INCREF(val);
  return val;
}

2、_PyDict_GetItem_KnownHash

/* Same as PyDict_GetItemWithError() but with hash supplied by caller.
  This returns NULL *with* an exception set if an exception occurred.
  It returns NULL *without* an exception set if the key wasn't present.
*/
PyObject *
_PyDict_GetItem_KnownHash(PyObject *op, PyObject *key, Py_hash_t hash)
{
  Py_ssize_t ix;
  PyDictObject *mp = (PyDictObject *)op;
  PyObject *value;

  if (!PyDict_Check(op)) {
    PyErr_BadInternalCall();
    return NULL;
  }

  ix = (mp->ma_keys->dk_lookup)(mp, key, hash, &value);
  if (ix < 0) {
    return NULL;
  }
  return value;
}

3、_PyDict_GetItemId

PyObject *
_PyDict_GetItemId(PyObject *dp, struct _Py_Identifier *key)
{
  PyObject *kv;
  kv = _PyUnicode_FromId(key); /* borrowed */
  if (kv == NULL) {
    PyErr_Clear();
    return NULL;
  }
  return PyDict_GetItem(dp, kv);
}

/* For backward compatibility with old dictionary interface */

4、PyDict_GetItemString

PyObject *
PyDict_GetItemString(PyObject *v, const char *key)
{
  PyObject *kv, *rv;
  kv = PyUnicode_FromString(key);
  if (kv == NULL) {
    PyErr_Clear();
    return NULL;
  }
  rv = PyDict_GetItem(v, kv);
  Py_DECREF(kv);
  return rv;
}

int
_PyDict_SetItemId(PyObject *v, struct _Py_Identifier *key, PyObject *item)
{
  PyObject *kv;
  kv = _PyUnicode_FromId(key); /* borrowed */
  if (kv == NULL)
    return -1;
  return PyDict_SetItem(v, kv, item);
}

int
PyDict_SetItemString(PyObject *v, const char *key, PyObject *item)
{
  PyObject *kv;
  int err;
  kv = PyUnicode_FromString(key);
  if (kv == NULL)
    return -1;
  PyUnicode_InternInPlace(&kv); /* XXX Should we really? */
  err = PyDict_SetItem(v, kv, item);
  Py_DECREF(kv);
  return err;
}

六、setdefault(k,v)

setdefault()表示去取字典中的key,如果取不到,则设置新值,相反如果取到,则返回原有默认值

1、dict_setdefault_impl 

/*[clinic input]
dict.setdefault
  key: object
  default: object = None
  /
Insert key with a value of default if key is not in the dictionary.
Return the value for key if key is in the dictionary, else default.
[clinic start generated code]*/

static PyObject *
dict_setdefault_impl(PyDictObject *self, PyObject *key,
           PyObject *default_value)
/*[clinic end generated code: output=f8c1101ebf69e220 input=0f063756e815fd9d]*/
{
  PyObject *val;

  val = PyDict_SetDefault((PyObject *)self, key, default_value);
  Py_XINCREF(val);
  return val;
}

static PyObject *
dict_clear(PyDictObject *mp, PyObject *Py_UNUSED(ignored))
{
  PyDict_Clear((PyObject *)mp);
  Py_RETURN_NONE;
}

/*[clinic input]
dict.pop
  key: object
  default: object = NULL
  /

2、PyDict_SetDefault

PyObject *
PyDict_SetDefault(PyObject *d, PyObject *key, PyObject *defaultobj)
{
  PyDictObject *mp = (PyDictObject *)d;
  PyObject *value;
  Py_hash_t hash;

  if (!PyDict_Check(d)) {
    PyErr_BadInternalCall();
    return NULL;
  }

  if (!PyUnicode_CheckExact(key) ||
    (hash = ((PyASCIIObject *) key)->hash) == -1) {
    hash = PyObject_Hash(key);
    if (hash == -1)
      return NULL;
  }
  if (mp->ma_keys == Py_EMPTY_KEYS) {
    if (insert_to_emptydict(mp, key, hash, defaultobj) < 0) {
      return NULL;
    }
    return defaultobj;
  }

  if (mp->ma_values != NULL && !PyUnicode_CheckExact(key)) {
    if (insertion_resize(mp) < 0)
      return NULL;
  }

  Py_ssize_t ix = (mp->ma_keys->dk_lookup)(mp, key, hash, &value);
  if (ix == DKIX_ERROR)
    return NULL;

  if (_PyDict_HasSplitTable(mp) &&
    ((ix >= 0 && value == NULL && mp->ma_used != ix) ||
     (ix == DKIX_EMPTY && mp->ma_used != mp->ma_keys->dk_nentries))) {
    if (insertion_resize(mp) < 0) {
      return NULL;
    }
    ix = DKIX_EMPTY;
  }

  if (ix == DKIX_EMPTY) {
    PyDictKeyEntry *ep, *ep0;
    value = defaultobj;
    if (mp->ma_keys->dk_usable <= 0) {
      if (insertion_resize(mp) < 0) {
        return NULL;
      }
    }
    Py_ssize_t hashpos = find_empty_slot(mp->ma_keys, hash);
    ep0 = DK_ENTRIES(mp->ma_keys);
    ep = &ep0[mp->ma_keys->dk_nentries];
    dictkeys_set_index(mp->ma_keys, hashpos, mp->ma_keys->dk_nentries);
    Py_INCREF(key);
    Py_INCREF(value);
    MAINTAIN_TRACKING(mp, key, value);
    ep->me_key = key;
    ep->me_hash = hash;
    if (_PyDict_HasSplitTable(mp)) {
      assert(mp->ma_values[mp->ma_keys->dk_nentries] == NULL);
      mp->ma_values[mp->ma_keys->dk_nentries] = value;
    }
    else {
      ep->me_value = value;
    }
    mp->ma_used++;
    mp->ma_version_tag = DICT_NEXT_VERSION();
    mp->ma_keys->dk_usable--;
    mp->ma_keys->dk_nentries++;
    assert(mp->ma_keys->dk_usable >= 0);
  }
  else if (value == NULL) {
    value = defaultobj;
    assert(_PyDict_HasSplitTable(mp));
    assert(ix == mp->ma_used);
    Py_INCREF(value);
    MAINTAIN_TRACKING(mp, key, value);
    mp->ma_values[ix] = value;
    mp->ma_used++;
    mp->ma_version_tag = DICT_NEXT_VERSION();
  }

  ASSERT_CONSISTENT(mp);
  return value;
}

七、update(dict)

update()是把两个字典合并成一个新的字典,中间有交叉的key,更新替换成新值,没有交叉就直接创建

1、dict_update_common

static int
dict_update_common(PyObject *self, PyObject *args, PyObject *kwds,
          const char *methname)
{
  PyObject *arg = NULL;
  int result = 0;

  if (!PyArg_UnpackTuple(args, methname, 0, 1, &arg)) {
    result = -1;
  }
  else if (arg != NULL) {
    if (PyDict_CheckExact(arg)) {
      result = PyDict_Merge(self, arg, 1);
    }
    else {
      _Py_IDENTIFIER(keys);
      PyObject *func;
      if (_PyObject_LookupAttrId(arg, &PyId_keys, &func) < 0) {
        result = -1;
      }
      else if (func != NULL) {
        Py_DECREF(func);
        result = PyDict_Merge(self, arg, 1);
      }
      else {
        result = PyDict_MergeFromSeq2(self, arg, 1);
      }
    }
  }

  if (result == 0 && kwds != NULL) {
    if (PyArg_ValidateKeywordArguments(kwds))
      result = PyDict_Merge(self, kwds, 1);
    else
      result = -1;
  }
  return result;
}

2、dict_update

static PyObject *
dict_update(PyObject *self, PyObject *args, PyObject *kwds)
{
  if (dict_update_common(self, args, kwds, "update") != -1)
    Py_RETURN_NONE;
  return NULL;
}

/* Update unconditionally replaces existing items.
  Merge has a 3rd argument 'override'; if set, it acts like Update,
  otherwise it leaves existing items unchanged.
  PyDict_{Update,Merge} update/merge from a mapping object.
  PyDict_MergeFromSeq2 updates/merges from any iterable object
  producing iterable objects of length 2.
*/

3、PyDict_Update

int
PyDict_Update(PyObject *a, PyObject *b)
{
  return dict_merge(a, b, 1);
}

八、items()将字典转换为列表

1、PyDict_Items

PyObject *
PyDict_Items(PyObject *mp)
{
  if (mp == NULL || !PyDict_Check(mp)) {
    PyErr_BadInternalCall();
    return NULL;
  }
  return dict_items((PyDictObject *)mp);
}

/* Return 1 if dicts equal, 0 if not, -1 if error.
 * Gets out as soon as any difference is detected.
 * Uses only Py_EQ comparison.
 */

九、fromkeys(list,默认值)

1、_PyDict_FromKeys

/* Internal version of dict.from_keys(). It is subclass-friendly. */
PyObject *
_PyDict_FromKeys(PyObject *cls, PyObject *iterable, PyObject *value)
{
  PyObject *it;    /* iter(iterable) */
  PyObject *key;
  PyObject *d;
  int status;

  d = _PyObject_CallNoArg(cls);
  if (d == NULL)
    return NULL;

  if (PyDict_CheckExact(d) && ((PyDictObject *)d)->ma_used == 0) {
    if (PyDict_CheckExact(iterable)) {
      PyDictObject *mp = (PyDictObject *)d;
      PyObject *oldvalue;
      Py_ssize_t pos = 0;
      PyObject *key;
      Py_hash_t hash;

      if (dictresize(mp, ESTIMATE_SIZE(PyDict_GET_SIZE(iterable)))) {
        Py_DECREF(d);
        return NULL;
      }

      while (_PyDict_Next(iterable, &pos, &key, &oldvalue, &hash)) {
        if (insertdict(mp, key, hash, value)) {
          Py_DECREF(d);
          return NULL;
        }
      }
      return d;
    }
    if (PyAnySet_CheckExact(iterable)) {
      PyDictObject *mp = (PyDictObject *)d;
      Py_ssize_t pos = 0;
      PyObject *key;
      Py_hash_t hash;

      if (dictresize(mp, ESTIMATE_SIZE(PySet_GET_SIZE(iterable)))) {
        Py_DECREF(d);
        return NULL;
      }

      while (_PySet_NextEntry(iterable, &pos, &key, &hash)) {
        if (insertdict(mp, key, hash, value)) {
          Py_DECREF(d);
          return NULL;
        }
      }
      return d;
    }
  }

  it = PyObject_GetIter(iterable);
  if (it == NULL){
    Py_DECREF(d);
    return NULL;
  }

  if (PyDict_CheckExact(d)) {
    while ((key = PyIter_Next(it)) != NULL) {
      status = PyDict_SetItem(d, key, value);
      Py_DECREF(key);
      if (status < 0)
        goto Fail;
    }
  } else {
    while ((key = PyIter_Next(it)) != NULL) {
      status = PyObject_SetItem(d, key, value);
      Py_DECREF(key);
      if (status < 0)
        goto Fail;
    }
  }

  if (PyErr_Occurred())
    goto Fail;
  Py_DECREF(it);
  return d;

Fail:
  Py_DECREF(it);
  Py_DECREF(d);
  return NULL;
}

2、dict_fromkeys_impl

static PyObject *
dict_fromkeys_impl(PyTypeObject *type, PyObject *iterable, PyObject *value)
/*[clinic end generated code: output=8fb98e4b10384999 input=382ba4855d0f74c3]*/
{
  return _PyDict_FromKeys((PyObject *)type, iterable, value);
}

static int
dict_update_common(PyObject *self, PyObject *args, PyObject *kwds,
          const char *methname)
{
  PyObject *arg = NULL;
  int result = 0;

  if (!PyArg_UnpackTuple(args, methname, 0, 1, &arg)) {
    result = -1;
  }
  else if (arg != NULL) {
    if (PyDict_CheckExact(arg)) {
      result = PyDict_Merge(self, arg, 1);
    }
    else {
      _Py_IDENTIFIER(keys);
      PyObject *func;
      if (_PyObject_LookupAttrId(arg, &PyId_keys, &func) < 0) {
        result = -1;
      }
      else if (func != NULL) {
        Py_DECREF(func);
        result = PyDict_Merge(self, arg, 1);
      }
      else {
        result = PyDict_MergeFromSeq2(self, arg, 1);
      }
    }
  }

  if (result == 0 && kwds != NULL) {
    if (PyArg_ValidateKeywordArguments(kwds))
      result = PyDict_Merge(self, kwds, 1);
    else
      result = -1;
  }
  return result;
}

/* Note: dict.update() uses the METH_VARARGS|METH_KEYWORDS calling convention.
  Using METH_FASTCALL|METH_KEYWORDS would make dict.update(**dict2) calls
  slower, see the issue #29312. */

十、Clea清空字典

1、PyDict_ClearFreeList

int
PyDict_ClearFreeList(void)
{
  PyDictObject *op;
  int ret = numfree + numfreekeys;
  while (numfree) {
    op = free_list[--numfree];
    assert(PyDict_CheckExact(op));
    PyObject_GC_Del(op);
  }
  while (numfreekeys) {
    PyObject_FREE(keys_free_list[--numfreekeys]);
  }
  return ret;
}

2、PyDict_Clea

void
PyDict_Clear(PyObject *op)
{
  PyDictObject *mp;
  PyDictKeysObject *oldkeys;
  PyObject **oldvalues;
  Py_ssize_t i, n;

  if (!PyDict_Check(op))
    return;
  mp = ((PyDictObject *)op);
  oldkeys = mp->ma_keys;
  oldvalues = mp->ma_values;
  if (oldvalues == empty_values)
    return;
  /* Empty the dict... */
  dictkeys_incref(Py_EMPTY_KEYS);
  mp->ma_keys = Py_EMPTY_KEYS;
  mp->ma_values = empty_values;
  mp->ma_used = 0;
  mp->ma_version_tag = DICT_NEXT_VERSION();
  /* ...then clear the keys and values */
  if (oldvalues != NULL) {
    n = oldkeys->dk_nentries;
    for (i = 0; i < n; i++)
      Py_CLEAR(oldvalues[i]);
    free_values(oldvalues);
    dictkeys_decref(oldkeys);
  }
  else {
    assert(oldkeys->dk_refcnt == 1);
    dictkeys_decref(oldkeys);
  }
  ASSERT_CONSISTENT(mp);
}

3、dict_clear

static PyObject *
dict_clear(PyDictObject *mp, PyObject *Py_UNUSED(ignored))
{
  PyDict_Clear((PyObject *)mp);
  Py_RETURN_NONE;
}

4、dict_tp_clear

static int
dict_tp_clear(PyObject *op)
{
  PyDict_Clear(op);
  return 0;
}

更多关于Python字典添加,删除,查询等相关操作方法的文章请查看下面的相关链接

Python 相关文章推荐
如何使用python爬取csdn博客访问量
Feb 14 Python
python实时分析日志的一个小脚本分享
May 07 Python
数组保存为txt, npy, csv 文件, 数组遍历enumerate的方法
Jul 09 Python
python实现抖音点赞功能
Apr 07 Python
浅谈python 中类属性共享的问题
Jul 02 Python
Python实现PyPDF2处理PDF文件的方法示例
Sep 25 Python
使用Python获取当前工作目录和执行命令的位置
Mar 09 Python
Tensorflow tf.tile()的用法实例分析
May 22 Python
python爬取网易云音乐热歌榜实例代码
Aug 07 Python
python操作redis数据库的三种方法
Sep 10 Python
利用python+ffmpeg合并B站视频及格式转换的实例代码
Nov 24 Python
Python装饰器详细介绍
Mar 25 Python
tensorflow之自定义神经网络层实例
Feb 07 #Python
在tensorflow中设置使用某一块GPU、多GPU、CPU的操作
Feb 07 #Python
谈一谈数组拼接tf.concat()和np.concatenate()的区别
Feb 07 #Python
python文件和文件夹复制函数
Feb 07 #Python
tf.concat中axis的含义与使用详解
Feb 07 #Python
浅谈tensorflow 中tf.concat()的使用
Feb 07 #Python
Python for循环通过序列索引迭代过程解析
Feb 07 #Python
You might like
php中使用explode查找某个字符是否存在的方法
2011/07/12 PHP
php使用pear_smtp发送邮件
2016/04/15 PHP
PHP 图片合成、仿微信群头像的方法示例
2019/10/25 PHP
js类中获取外部函数名的方法
2007/08/19 Javascript
javascript Excel操作知识点
2009/04/24 Javascript
jquery.validate使用攻略 第一部
2010/07/01 Javascript
Jquery动态替换div内容及动态展示的方法
2015/01/23 Javascript
JavaScript去除数组里重复值的方法
2015/07/13 Javascript
简单的jQuery banner图片轮播实例代码
2016/03/04 Javascript
Javascript在IE和Firefox浏览器常见兼容性问题总结
2016/08/03 Javascript
原生态js,鼠标按下后,经过了那些单元格的简单实例
2016/08/11 Javascript
jstree单选功能的实现方法
2017/06/07 Javascript
js模拟百度模糊搜索的实例
2017/08/04 Javascript
详解让sublime text3支持Vue语法高亮显示的示例
2017/09/29 Javascript
自定义vue组件发布到npm的方法
2018/05/09 Javascript
AngularJS模态框模板ngDialog的使用详解
2018/05/11 Javascript
vue-next/runtime-core 源码阅读指南详解
2019/10/25 Javascript
微信小程序使用GoEasy实现websocket实时通讯
2020/05/19 Javascript
Python open读写文件实现脚本
2008/09/06 Python
Python中.join()和os.path.join()两个函数的用法详解
2018/06/11 Python
flask入门之表单的实现
2018/07/18 Python
Python图像处理之简单画板实现方法示例
2018/08/30 Python
python argparser的具体使用
2019/11/10 Python
pytorch的梯度计算以及backward方法详解
2020/01/10 Python
100%有机精油,美容油:House of Pure Essence
2018/10/30 全球购物
什么是静态路由?什么是动态路由?各自的特点是什么?
2015/09/16 面试题
职业生涯规划书基本格式
2014/01/06 职场文书
活动志愿者自荐信
2014/01/27 职场文书
蓝颜请假条
2014/04/11 职场文书
《永远的白衣战士》教学反思
2014/04/25 职场文书
职务说明书范文
2014/05/07 职场文书
见习报告怎么写
2014/10/31 职场文书
党员民主生活会材料
2014/12/15 职场文书
奶茶店的创业计划书该怎么写?
2019/07/15 职场文书
Python中seaborn库之countplot的数据可视化使用
2021/06/11 Python
spring boot中nativeQuery的用法
2021/07/26 Java/Android